Quick Softwares

μClinux

2008-06-08T01:31:00.000-07:00

μClinux stands for "MicroController Linux", and is pronounced "you-see-Linux" as explained in the website and not how the letter mu is normally pronounced. It was a fork of the Linux kernel for microcontrollers (µCs: see embedded systems) without a memory management unit (MMU). It was integrated into the main line of development as of 2.5.46; the project continues to develop patches and tools for microcontrollers.

Introduction
μClinux was originally created by D. Jeff Dionne and Kenneth Albanowski in 1998. Initially they targeted the Motorola DragonBall family of embedded 68k processors (specifically the 68328 series) on a 2.0.33 Linux kernel. After releasing their initial work a developer community soon sprung up to extend their work to newer kernels and other microprocessor architectures. In early 1999 support was added for the Motorola (now Freescale) ColdFire family of embedded microprocessors. ARM processor support also became available later that year.

Although originally targeting 2.0 series Linux kernels, it now has ports based on Linux 2.4 and Linux 2.6. There were never any μClinux extensions applied to the 2.2 series kernels.

Since version 2.5.46 of the Linux kernel the major parts of μClinux have been integrated with the main line kernel for a number of processor architectures. Greg Ungerer (who originally ported μClinux to the Motorola ColdFire family of processors) continues to maintain and actively push core μClinux support into 2.6 series Linux kernels. In this regard μClinux is essentially no longer a separate fork of Linux.

The project continues to develop patches and supporting tools for using Linux on microcontrollers. μClinux has support for many architectures, and forms the basis of many products, like network routers, security cameras, DVD or MP3 players, VoIP phone or Gateways, scanners, and card readers.

Supported architectures

The current list includes:
Altera NIOS
ADI Blackfin
ARM
ETRAX
Freescale M68K (including DragonBall, ColdFire, PowerQUICC and others)
Fujitsu FRV
Hitachi H8
Intel i960
MIPS (example: the Brecis parts)
NEC V850E
Xilinx MicroBlaze

Recent developments
Quality of support varies, with some ports no longer under active development. ARM support is currently being merged, most core support is in later 2.6 series kernels. Microblaze is actively attempting for inclusion in main line Linux kernels. Development for some architectures has occurred outside of the existing μClinux community (typically by commercial interests, but sometimes by individuals), and resources like the uclinux.org web site may not be particularly helpful for all architecture types.

Like any part of the Linux kernel, the extensions (in the form of patches) are licensed under the GPL.

Although strictly speaking μClinux is only the operating system kernel, the μClinux project also produced a C standard library called uClibc (now separately maintained) and a "userland" which can be used as a complete operating system for embedded systems called "μClinux-dist".

The "μClinux-dist" software package contains libraries, applications and tools. It can be configured and built into a kernel with root file system. It was first released by Greg Ungerer in 1999 as the μClinux-coldfire package. In the following years it came to support many architecture families, and now can even build standard Linux architectures (such as x86) as well.

The "μClinux-dist" userland utilities contain tiny http servers, a small 'sh like' shell, and even a fun ascii art Star Wars film. It also contains many other well known Open Source packages, like Samba and FreeS/WAN, all of which run on μClinux systems.

For example, the iPodLinux project uses μClinux for its kernel, and so does Mattel's Juice Box, as well as the well-known Nintendo DS Linux port, DSLinux, the lesser-known PlayStation port Runix, and the PlayStation Portable port.

It has also been used in the Picotux, advertised as the smallest computer running Linux in the world. The Pictotux 100 is 35 mm × 19 mm × 19 mm, but the Blackfin based Minotaur BF537 is smaller, at 26.5mm x 26.5mm x 4.2mm.

DejaGnu

2008-06-08T01:27:00.000-07:00

DejaGnu is a framework for testing other programs. It has a main script called runtest that goes through a directory looking at configuration files and then runs some tests with given criteria. The purpose of the DejaGnu package is to provide a single front end for all tests. It is a part of the GNU project and as such is under the GPL. It is based on Expect, which is in turn based on Tcl. The current maintainers are Rob Savoye, and Ben Elliston.

Testing

DejaGnu has a very strong history in testing due to its Tcl base. Tcl is used extensively by companies such as Oracle and Sybase to test their products. DejaGnu allows this work to be much more structured.

The tests can be grouped according to the tool they are testing. The test is run by merely calling runtest in the root project directory.

runtest --tool program_to_test

This will look in the testsuite directory for any folders starting with program_to_test and will run all .exp files in that folder.

Embedded Design

One field to which DejaGnu is well suited is that of embedded design. It allows testing to be done remotely on development boards. Also, separate initialization files can be creating for each operating system and board. This focus on embedded targets and remote hosts is the source of its popularity with many GNU projects, universities, and private companies.

Files

Essential Files

testsuite

apache Each directory in testsuite should contain tests for a specific tool. In this example, the tool(program) being tested is apache, the webserver.
apache.test1.exp This will be the file containing some of your tests. In the fictional case of testing apache, these tests might contain such code to change configuration options, then connect to the network and check to make sure the changes have taken effect.

config
unix.exp
lib
whois.exp This file will be run as a tool init file.
Other Files

site.exp This file is a directory specific configuration file for runtest. If you always use the same options, you may want to put them here rather than typing them every time. You can record any variables that you'd be able to use as a command line argument.

set tool apache #run tests on apache
set srcdir ./testsuite #look here fore test files
set outdir ./logs #save the logs in a separate directory
set all 1 #show results from all tests (rather than just ones with errors)

.dejagnurc This is a personal configuration file. Each developer can have their own one to personalize their current DejaGnu operating environment. This file should be located in the user's home directory (~/.dejagnurc)
global_config.exp This is the first configuration file loaded. It can be named anything but must be pointed to by the $DEJAGNU environment variable (set when your terminal loads).

wxWidgets

2008-06-02T13:14:00.000-07:00

wxWidgets (formerly wxWindows) is a widget toolkit for creating graphical user interfaces (GUIs) for cross-platform applications. wxWidgets enables a program's GUI code to compile and run on several computer platforms with minimal or no code changes. It covers systems such as Microsoft Windows, Mac OS, Linux/Unix (X11, Motif, and GTK+), OpenVMS, OS/2 and AmigaOS. A version for embedded systems is under development.

History

wxWidgets (initially wxWindows) was started in 1992 by Julian Smart at the University of Edinburgh. He attained an honours degree in Computational Science from the University of St Andrews in the year 1986, and is still a core developer.

On February 20 2004, the developers of wxWindows announced that the project was changing its name to wxWidgets, as a result of requests from Microsoft of Julian Smart to respect Microsoft's United Kingdom trademark of the term Windows.

License

wxWidgets is distributed under a custom made licence, similar to the GNU Lesser General Public License, with an exception stating that derived works in binary form may be distributed on the user's own terms. This licence is a free software licence, making wxWidgets free software.

Implementation

The wxWidgets library is implemented in C++, with bindings available for many commonly used programming languages, among them, Python (wxPython), Erlang (wxErlang), Haskell (wxHaskell), Lua (wxLua), Perl (wxPerl), Ruby (wxRuby), Smalltalk (wxSqueak), Java (wx4j) and even JavaScript (wxJavaScript). For a complete list, with links to the respective project sites, see the external references at the end of this article. There is also PLT Scheme, which uses an incompatible branch of wxWindows (version 1), created in 1995. The toolkit is deeply integrated with the language run-time (garbage collection, resource administration) unlike in other languages, which simply provide a library binding.

wxWidgets is best described as a native mode toolkit as it provides a thin abstraction to a platform's native widgets, as opposed to emulating the display of widgets using graphic primitives. Calling a native widget on the target platform results in a more native looking interface than toolkits such as Swing (for Java), as well as offering performance and other benefits.

The toolkit is also not restricted to GUI development, having a built-in ODBC-based database library, an inter-process communication layer, socket networking functionality, and more.

Mambo

2008-05-27T00:42:00.000-07:00

Mambo (formerly named Mambo Open Source or MOS) is a free software / open source content management system (CMS) for creating and managing websites through a simple web interface. It has attracted many users due to its ease of use. Mambo also includes more advanced features such as page caching to improve performance on busy sites, advanced templating techniques, and a fairly robust API. It can also automate many tasks such as web indexing for static pages. Mambo can provide RSS feeds, printable versions of pages, news flashes, blogs, forums, polls, calendars, website searching, language internationalization, and other possibilities.

Mambo is released under the terms of the GNU General Public License (GPL)Version 2. It is written with the PHP programming language and uses the MySQL database.

The rights to the Mambo CMS codebase, name and copyrights, are protected by the Mambo Foundation, a non-profit corporation formed to support and promote the Mambo Open Source project.

The project site and downloads can be found at http://source.mambo-foundation.org, and an online demo of Mambo is available at Open Source CMS Demo.

Requirements

As of 24 April 2007, the minimum requirements for Mambo consist of:

* Apache (version 1.3.19 or above) or Windows IIS
* MySQL (version 4.x or above)
* PHP (version 4.3.x or above with extensions: mysql, xml, zlib, ftp)

Mambo is thoroughly tested on Linux, FreeBSD, Mac OS X and Windows NT/2000/XP/Vista. Linux or one of the BSD's are recommended, but anything else that can run the three pieces of software listed above should work. Additionally, Mambo displays properly in most major browsers: Internet Explorer (version 5.5+), Netscape, Opera and Mozilla/Firefox.

PHP must have been compiled with support for MySQL and Zlib in order to successfully run Mambo. Mambo works on Microsoft IIS, but Apache is recommended for running Mambo on Windows.

Mambo Foundation

The Mambo Foundation is a non-profit entity established under the laws of Australia. The Foundation is based on Eclipse and GNOME and is controlled by the members of the Foundation via an elected Board of Directors. The Mambo Foundation's brief is to foster the development of the Mambo system and to shelter the project from threats and misuse. The Foundation was formed in August 2005. The Mambo Foundation also has forums addressing the latest issues within Mambo, including the deployment of Mambo 5.

Timeline of Mambo History

* 2000: Miro Construct Pty Ltd, registered in March 2000 in Melbourne, and headed up by CEO Peter Lamont, a former advertising executive, starts development of Mambo, a closed-source, proprietary content management system.

* 2001: The company adopted a dual licensing policy, releasing Mambo Site Server under the GPL on Sourceforge in April 2001.

* May 2001: The mamboserver.com domain name is registered.

* From this time until the middle of 2002, Miro was the only developer of Mambo, contributing bug-fixes and security patches but not really extending the code or adding to the feature sets.

* 2002: Miro releases the commercial CMS called Mambo 2002.

* With version 3.0.x, the open source Mambo Site Server becomes "Mambo Open Source" (commonly referred to as "MOS").

* Robert Castley becomes Project Director of Mambo Open Source.

* By the end of 2002, Robert Castley had pulled together a volunteer team of developers.

* Mambo Open Source 4.0 is released.

* 2003: Early in 2003, Miro hands off the responsibility of the code fully to the Open Source project Development Team.
* Miro concentrates on its commercial products and Mambo Open Source goes from strength to strength under the leadership of Robert Castley.

* Miro released Mambo CMS, a commercial version of Mambo Open Source. Miro claims that Mambo CMS does not contain any source added to Mambo after it was made open source.

* Miro Construct Pty Ltd goes into voluntary liquidation in February 2003 and in August, Miro International Pty Ltd is formed. Source code for Mambo Open Source shows copyright 2000 - 2003 Miro Construct Pty Ltd.

* Mambo Open Source 4.5 released in December 2003. By this time, almost all of the original Miro code had disappeared during refactoring.

* 2004: mamboforge.net starts in March, 2004.

* Linux Format awards Mambo “Best Free Software Project” of the Year.

* Linux User and Developer names it “Best Linux or Open Source Software”.

* In mid-2004, the name "Mambo Open Source" (which was commonly referred to as MOS) was changed to just "Mambo", causing concern in the community over apparent confusion this would cause between the open source, community-developed CMS and Miro's commercial offering, "Mambo CMS".

* In late 2004, Mambo was targeted by legal threats concerning the intellectual property rights to certain pieces of code contained in the core. The problem was severe and cost money, man hours, and eventually the loss of some key community leaders. Miro came to the aid of Mambo, offering legal and corporate resources to protect the development team and preserve the program.

* September 2004: Mambo version 4.5.1 is released, followed a month later by version 4.5.1a stable.

* Robert Castley resigns as Project Director and in November, Andrew Eddie takes on the role.

* December 2004: the Mambo Steering Committee was established with representatives from both Miro and the Mambo development team. This committee was designed to govern the Mambo project.

* January 2005: Andrew Eddie announces a strategic partnership between Mambo and Miro International Pty Ltd, with Miro proposing to offer financial support for the open source project, plus training, commercial support services, and developer certification.

* February 2005: Discussions begin over the formation of a non-profit foundation for the Mambo project.

* Versions 4.5.2 and later, 4.5.2.1 are released.

* April 2005: The commercial Mambo CMS is renamed "Jango".

* “Best Open Source Solution” and “Best of Show - Total Industry Solution” at LinuxWorld Boston.

* “Best Open Source Solution” at LinuxWorld San Francisco.

* July 2005: mambo-foundation.org domain is established.

* August 2005: Mambo Foundation, Inc is legally constituted on 8th August, 2005. Miro CEO Peter Lamont appoints himself President of the Board of the new Foundation.

* 12th August: Robert Castley, who is an inaugural member of the Mambo Foundation Board of Regents, states: "The Foundation allows for everything to be placed outside of Miro incl. Domain Names, hosting etc. " and goes on to say that with him, the original founder of Mambo Open Source, and Andrew Eddie both being on the Board of the Mambo Foundation, Mambo would continue as a successful, open source project. He concluded his statement with,"So there you have it two very key people in the overall success of Mambo are at the helm. Trust me, Mambo is in very, very safe hands!"

* A few days later, the entire team of core programmers publicly announced they had abandoned Mambo and shortly after this, Robert Castley steps down from the Board of Regents.

* The former core development team members regroup under the name "Open Source Matters" and the open source community at mamboserver.com fractures over allegations that the Mambo Foundation was formed without community input and with insufficient developer control. People express suspicion over the level of involvement by Miro International. By the end of August, the new project is named Joomla! and most of the former Mambo community has relocated to Open Source Matters. By the end of September, Open Source Matters Inc is a duly constituted non-profit corporation registered in New York.

* Joomla! positions itself as a "rebranding of Mambo" and releases its first fork of Mambo as Joomla 1.0 in September, 2005. The two code-bases are almost identical at this stage.

* Mambo forms a new core development team with Martin Brampton appointed as Core Development Team leader.

* Miro assigns all rights in the copyright of Mambo to the Mambo Foundation.

* November 2005: Mambo version 4.5.3 is released.

* December 2005: Miro International Pty Ltd is voluntarily deregistered as a company on 31st December, 2005.

* January 2006: The rights to Miro International Pty Ltd are sold by Peter Lamont and a new business entity called Miro Software Solutions is created. Miro Software Solutions continues to develop Jango and other proprietary software under new ownership.

* March 2006: Mambo named "Best Open Source Software Solution" at LinuxWorld Australia.

* April 2006: Core developer team leader, Martin Brampton, resigns and leaves the project. Chad Auld takes over the role as Core Developer Team leader.

* Mambo 4.5.4 is released.

* July 2006: The Mambo Foundation websites become independent from Mambo Communities Pty Ltd.

* Following elections, the new Board of the Mambo Foundation takes office. The Mambo Foundation is now completely independent of any corporate interest.

* September 2006: Mambo version 4.6 is released.

* October 2006: Mambo 4.6.1 is released.

* February 2007: Mambo 4.5.5 is released. This is a maintenance release for the 4.5.x branch.

* April 2007: Mambo 4.6.2 is released. This is a maintenance release for the 4.6.x branch and enables localisation of Mambo.
* December 2007: Mambo 4.6.3 is released. This is a security and maintenance release.
* January 2008: Mambo 4.5.6 is released. This is the final release of the Mambo 4.5 branch.
* February 2008: Chad Auld leaves the project.
* March 2008: John Messingham becomes Project Leader. Ozgur Cem Sen becomes core development team leader. Ozgur Cem Sen leaves the project shortly thereafter.

Future development

The next major release of Mambo (5.0) will undertake a complete rewrite, and it will be based upon the open source web application framework CakePHP.

Awards

* "Best Free Software Project of the Year" - Linux Format Magazine, 2004
* "Best Linux or Open Source Software" - LinuxUser & Developer 2004
* "Best Open Source Solution" - LinuxWorld, Boston 2005
* "Best of Show - Total Industry Solution" - LinuxWorld, Boston 2005
* "Best Open Source Solution" - LinuxWorld, San Francisco 2005
* "Best Open Source Solution" LinuxWorld, Sydney, Australia 2006

Joomla

2008-05-27T00:38:00.000-07:00

Joomla! is a free, open source content management system for publishing content on the world wide web and intranets. The system includes features such as page caching to improve performance, RSS feeds, printable versions of pages, news flashes, blogs, polls, website searching, and language internationalization. Joomla is licensed under the GPL, and is the result of a fork of Mambo.

The name Joomla is properly written with an exclamation mark as that is part of the name, but this is commonly omitted.

It is written in the PHP programming language and uses the MySQL database by default.

History

Joomla! came into being as the result of a fork of Mambo by the development team on August 17, 2005. At that time, the Mambo name was trademarked by Miro International Pty Ltd, who formed a non-profit foundation with the stated purpose to fund the project and protect it from lawsuits. The development team claimed that many of the provisions of the foundation structure went against previous agreements made by the elected Mambo Steering Committee, lacked the necessary consultation with key stake holders, and included provisions that violated core open source values.

The development team created a web site called OpenSourceMatters to distribute information to users, developers, web designers, and the community in general. The project team leader Andrew Eddie, aka "MasterChief" wrote an open letter to the community which appeared on the announcements section of the public forum at mamboserver.com.

A thousand people had joined the opensourcematters.org web site within a day, most posting words of encouragement and support. The web site received the slashdot effect as a result. Miro CEO Peter Lamont gave a public response to the development team in an article entitled "The Mambo Open Source Controversy - 20 Questions With Miro".

This event stirred deeply held feelings in the free software community regarding what shall constitute "open source". Forums at many other open source projects were active with postings for and against the actions of both sides.

In the two weeks following Eddie's announcement teams were re-organized and the community continued to grow. Eben Moglen and the Software Freedom Law Center (SFLC) assisted the Joomla! core team beginning in August 2005, as indicated by Moglen's blog entry from that date and a related OSM announcement. The SFLC continue to provide legal guidance to Joomla! project.

On August 18, 2005, Andrew Eddie called for community input on suggested names for the project. The development team indicated that it would make the final decision for the project name based on community input. The name the development team chose was not in the list of suggested names provided by the community as it was chosen with consultation from a professional brand consultancy under the pay of Open Source Matters.

On September 1, 2005 the new name, "Joomla", which is the English spelling of the Swahili (Arabic:جملة ,and Urdu: جملہ ) word jumla meaning "all together" or "as a whole" was announced.

On September 7, 2005, the development team called for logo submissions from the community, invited the community to vote on the logo preferred, and announced the community's decision on September 22, 2005. Following the logo selection, Brand Guidelines, a Brand Manual, and set of Logo Resources were published on October 2, 2005 for the community's use.

The first release of Joomla (Joomla 1.0.0) was announced on September 16, 2005. This was a re-branded release of Mambo 4.5.2.3 combined with other bug and moderate-level security fixes. Joomla version 1.5 was released on January 22, 2008. Joomla won the Packt Publishing Open Source Content Management System Award in 2006 and 2007.

Features

The Joomla package consists of many different parts, which are built to be as modular as possible, allowing extensions and integrations to be made easily. An example of such are extensions called "Plugins". (Previously known as "Mambots".) Plugins are background extensions that extend Joomla with new functionality. The WikiBot, for example, allows the author of Joomla content to use "Wikitags" in Joomla articles which will auto-create dynamic hyperlinks to Wikipedia articles when displayed. There are over 3,100 extensions for Joomla available via the Extensions Directory.

In addition to Plugins, more comprehensive extensions are available. "Components" allow webmasters to perform such tasks as build a community by expanding user features, backup a website, translate content and create URLs that are more friendly to search engines. "Modules" perform such tasks as displaying a calendar or allowing custom code like Google AdSense etc to be inserted within the base Joomla code.

Since it has been around longer, there are more extensions available for Joomla 1.0 than for Joomla 1.5, although native 1.5 extensions are becoming increasingly available. Some of the older 1.0 extensions can be used with version 1.5 if it is set to legacy mode.

Joomla permits administrators to set global configuration parameters that affect all articles. Every page conforms to these parameters by default, but a page can have its own setting for each parameter. For example, you can elect to show the article author, hide the author, or simply go with the global "show author" parameter.

Community

Joomla has an official and many unofficial communities. As of February 2008, the official Joomla forum has more than 260,000 threads and over 1.2 million posts from more than 170,000 registered members in 40 languages. Unofficial sites are published in many languages, often with Joomla extensions that are region specific. Bi-directional text support for the Hebrew and Arabic languages, for example, can be found on 3rd party community portals. Unofficial web developers also build extensions and web templates for commercial sale and offer freelance customization services. Usually a template is distributed as a zip file which can be installed using the Joomla installer.

Yet Another Setup Tool

2008-05-24T06:42:00.000-07:00

Yet another Setup Tool (YaST), is an operating system setup and configuration tool that is featured in the openSUSE linux distribution, as well as Novell's derived commercial distributions. It is also part of the defunct United Linux. AutoYaST allows unattended and automated installation and is based on YaST. The first SuSE distribution that included YaST was released in May, 1996.

YaST is free software that Novell has made available under the GPL.

YaST2 is a tool for administering and maintaining a SUSE Linux installation. It allows administrators to install software, configure hardware, set up networks and servers, and more.

A feature of YaST is that it contains both GUI and ncurses front ends. This is especially useful for non-GUI installations, for system administration over slow Internet connections, and for when one is unable to boot into a graphical X server but still requires an advanced user interface to the package manager (for example, a novice user trying to downgrade an Xorg package to fix a graphical installation).

YaST's display configuration module is called SaX2 (which stands for SUSE Automated X configuration, version 2).

OpenSUSE 10.3 features a redesigned YaST for GNOME users. Among the new modules are the "Community Repositories" which is a tool to easily add much used repositories and the KIWI imaging tool which easily lets you roll out your own custom SUSE images.

YaST offers package management functionality through the ZYpp project. The first ZYpp enabled package management YaST applications had performance problems and long start up times, but was improved in the 10.2 and 10.3 releases. Starting with openSUSE 11.0 alpha 3, ZYpp was integrated with the SAT solver project, moving YaST & zypper ahead of other rpm based package managers in terms of speed.

AutoYaST is a system for installing one or more openSUSE systems automatically without user intervention. AutoYaST installations are performed using a control file with installation and configuration data. The profile of each current system is stored in /root/autoyast.xml.

Yellow dog Updater, Modified

2008-05-24T06:37:00.000-07:00

The Yellow dog Updater, Modified (YUM) is a free software/open source command line package management utility for RPM-compatible Linux operating systems. It was developed by Seth Vidal and a group of volunteer programmers, and is currently maintained as part of Duke University's Linux@DUKE project. Though yum is a command line utility, several other tools provide graphical user interfaces to yum, among them pup, pirut, and yumex. Seth Vidal now works for Red Hat and a number of other Red Hat programmers are involved in the development of yum.

Yum is a full rewrite of its predecessor tool, Yellowdog Updater (YUP), and was developed primarily in order to update and manage Red Hat Linux systems used at the Duke University department of Physics. Since then, it has been adopted by Fedora, CentOS, and many other RPM-based Linux distributions, including Yellow Dog Linux itself, where it has replaced the original YUP utility. Red Hat's own enterprise package manager, up2date, can also make use of yum repositories when performing software updates. Red Hat Enterprise 5 saw yum and pirut replace up2date in that distribution.

Automatic software update can be done with either the yum-updatesd or the yum-updateonboot packages.

Yum's repository system is quickly becoming the standard for RPM-based repositories. Besides the distributions that use Yum directly, SUSE Linux 10.1 adds support for Yum repositories in YaST, and the openSUSE Build Repository is exclusively Yum-based.

Yellow dog Updater, Modified is available under the GNU GPL license version 2 or above.

Yum repositories

Creation of yum repositories is handled by a separate tool called "createrepo", which generates the necessary XML metadata.

The mrepo tool (formerly known as Yam) can help in the creation and maintenance of repositories.

Plug-in/module system

In the 2.x versions of yum, an interface for programming extensions in Python has been added that allows the behavior of yum to be altered.

Graphical interfaces

* Pirut - default Fedora GUI as of Fedora Core 5
* Pup - Package Updater Fedora GUI
* Yum Extender - Alternative Fedora GUI for Yum
* KYum - GUI for Yum on KDE

Scalix

2008-05-23T00:54:00.000-07:00

Scalix is an open source e-mail and groupware server that runs on Linux, licensed under the Scalix Public License (SPL). It was previously proprietary software.

It was based on HP OpenMail, which was licensed from Hewlett Packard. It provides e-mail, calendars and other collaborative software, which are standard in groupware. It can be accessed from many different clients, most notably Microsoft Outlook, Novell Evolution (formerly Ximian) and Scalix Web Access, an AJAX-based web email and calendaring client that combines the functionality of desktop email with the ease-of-use of a browser.

Scalix was originally made by Scalix Corporation, based in California, with offices in New York, Germany, the United Kingdom, Malaysia and Japan. They also had contract operations in India, Russia and the United Kingdom. In July 2007, the company was purchased by Xandros.

Scalix includes and provides the following components as part of its offerings:

* Scalix email and calendar server, a full-featured messaging and collaboration server based on Linux and open source
* ScalixConnect for Outlook, robust third-party native and transparent Outlook support
* Scalix Web Access, an AJAX-based cross-browser, cross-platform email and calendaring client that combines desktop email functionality with the convenience of a browser
* ScalixConnect for Evolution, full-function email and calendaring client support for Linux desktop users
* Scalix Wireless Solution, advanced wireless email/PIM support for Blackberries, Treos and Smartphones
* Scalix Administration Console, AJAX-based web client for administering the Scalix server and email users
* ScalixReady for Open Source and Commercial messaging ecosystem components, which certifies that third party software works with Scalix
* MS Ecosystem Interoperability for seamless co-existence with MS Exchange and Active Directory
* Individual email level backup / restore when using SepSesam

Scalix comes in several different editions: Enterprise, Small Business, Appliance, Xandros, Community and Raw, the latter two being free software.

Xandros claims there are 250 Scalix-capable partners and affiliates, worldwide.

Software License

The Scalix Public License is based on the Mozilla Public License (MPL); the modifications have not been approved by the Open Source Initiative. The SPL adds an appendix (exhibit b) to the MPL requiring that any products derived from Scalix source code display a "Scalix" logo that links back to the Scalix website, and a copyright notice "in the same form as the latest version of the Covered Code distributed by Scalix at the time of distribution of such copy"; see the license for details.

Gobuntu

2008-05-23T00:40:00.000-07:00

Gobuntu is an official derivative of the Ubuntu operating system, aiming to provide a distribution consisting entirely of free software.

History and development process

Mark Shuttleworth first mentioned the idea of creating an Ubuntu derivative named Gnubuntu consisting entirely of free software, on November 24, 2005. Due to Richard Stallman's disapproval of the name, the project was later renamed to Ubuntu-libre.[3] Stallman has previously endorsed a distribution based on Ubuntu called gNewSense, and has criticized Ubuntu for using proprietary and non-free software in successive distributions, most notably, Ubuntu 7.04.

While introducing Ubuntu 7.10, Mark Shuttleworth said that it will
“Feature a new flavour - as yet unnamed - which takes an ultra-orthodox view of licensing: no firmware, drivers, imagery, sounds, applications, or other content which do not include full source materials and come with full rights of modification, remixing and redistribution. There should be no more conservative home, for those who demand a super-strict interpretation of the "free" in free software.”

Gobuntu was officially announced by Mark Shuttleworth on July 10, 2007, and daily builds of Gobuntu 7.10 began to be publicly released. The initial version, Gobuntu 7.10, was released on October 18, 2007, but only in text-only installer. The first full release is expected to be the Long-Term Release codenamed "Hardy Heron", but, despite an announcement of plans to the contrary, the official mirrors do not carry a 8.04 release as of April 26, 2008. This may be related to Shuttleworth's post, where he suggests Gobuntu developers might want to concentrate their efforts on the, FSF-approved, gNewSense, instead of Gobuntu, which he considers a failed effort.

Limitations

Because some drivers, firmware, and "binary blobs" were removed from Gobuntu, it will run on fewer computers than Ubuntu. Canonical states:

Please note that because running Gobuntu on most laptops and many desktops will be difficult, Gobuntu is intended for experienced Linux enthusiasts at this time.

Early Criticism

Release 7.10 initially met with criticism from some free software advocates, since it included Mozilla Firefox and Mozilla Thunderbird, which is not considered to be 100% free software, by the strict definition of GPL, because they include "non-free" artwork.
After some debate on the developer list, this problem was quickly addressed by Canonical, and the non-free programs will be replaced in the upcoming release, Hardy Heron, in which Firefox will be replaced by Epiphany.

PackageKit

2008-05-22T05:58:00.000-07:00

PackageKit is a suite of software applications designed to provide a consistent and high-level front end for a number of different package management systems. PackageKit was created by Richard Hughes.

The suite is ostensibly cross-platform, though it is primarily targeted at Linux distributions which follow the interoperability standards set out by the freedesktop.org group. It uses the software libraries provided by the D-Bus and PolicyKit projects to handle inter-process communication and computer privilege negotiation.

Released under the terms of the GNU General Public License, PackageKit is free software.

History

PackageKit was created by Richard Hughes and first proposed in a series of blog posts in 2007, and is now developed by a small team of developers. Fedora 9 is the first Linux distribution to use it as default front end for yum.

Design

PackageKit itself is a system activated daemon called packagekitd, that abstracts out differences between the different systems. A library called libpackagekit also allows other programs to trivially interact with PackageKit.

Features include:

* Installing local files, ServicePack media and from remote sources.
* Authentication using PolicyKit
* Does not replace existing packaging tools
* Fast user switch aware -- will not allow shutdown in critical parts of the transaction
* A system activated daemon so does exits when not in use

Backends

A number of different package management systems (known as backends) support different abstract methods and signals that are used by the front-end tools. Backends supported include Advanced Packaging Tool, alpm, box, Conary (package manager), opkg, PiSi, poldek, Smart Package Manager, Yellow dog Updater, Modified and zypp.

Frontends

gnome-packagekit is the name of the collection of software application front ends for PackageKit to be used in the GNOME desktop. Also released under the terms of the GNU General Public License, gnome-packagekit is free software.

OpenJDK

2008-05-22T05:48:00.000-07:00

OpenJDK is the effort by Sun Microsystems to release a fully buildable Java Development Kit based completely on free and open source code.

History

Sun's promise and initial release

Sun announced in JavaOne 2006 that Java would become Open Source, and on October 25, 2006, at the Oracle OpenWorld conference, Jonathan Schwartz said that the company was set to announce the open-sourcing of the core Java Platform within 30 to 60 days.

Sun released the Java HotSpot virtual machine and compiler as free software under the GNU General Public License on 13 November 2006, with a promise that the rest of the JDK (which includes the JRE) would be placed under the GPL by March 2007 ("except for a few components that Sun does not have the right to publish in source form under the GPL"). According to Richard Stallman, this would mean an end to the Java trap. Mark Shuttleworth called the initial press announcement, "A real milestone for the free software community".

Release of the class library

Following their promise to release a fully buildable JDK based almost completely on free and open source code in the first half of 2007 , Sun released the complete source code of the Class library under GPL on May 8, 2007, except some limited parts that were licensed by Sun from 3rd parties who did not want their code to be released under an open-source license.[5]. Included in the list of encumbered parts were several major components of the Java GUI system. Sun stated that their goal was to replace the parts that remain closed with alternative implementations and make the class library completely open.

Community improvements

On 2007-11-05, Red Hat announced an agreement with Sun Microsystems, signing Sun's broad contributor agreement (that covers participation in all Sun-led open source projects by all Red Hat engineers) and Sun's OpenJDK Community TCK License Agreement (That gives the company access to the test suite that determines whether a project based on openJDK complies with the Java SE 6 specification).

Also on November 2007, the porters group was created on OpenJDK to aid in efforts to port OpenJDK to different CPU architectures and operating systems. The BSD porting projects, led by Kurt Miller and Greg Lewis and the Mac OS X porting project (based on the BSD one) SoyLatte led by Landon Fuller have expressed interest in joining OpenJDK via the porters group and as of January 2008 are part of the mailing list discussions. Another project pending formalization on the porters group is the Haiku Java Team, led by Bryan Varner.

On December 2007, Sun moved the revision control of OpenJDK from TeamWare to Mercurial, as part of the process of releasing it to open source communities.

OpenJDK has comparatively very strict procedure of accepting code contributions from the side: every proposed contribution must be reviewed by two of Sun's engineers and have the automatic test demonstrating that feature has been fixed. This ensures the persistent high quality of the code but also means that even a trivial fix may take many weeks to approve.

Inclusion in Linux distributions

As of May 2008, the Fedora 9 and Ubuntu 8.04[15] distributions were released with OpenJDK, based completely on free and open source code[16].

OpenJDK doesn’t pass all of the compatibility tests in the Java SE 6 JCK yet, because of the remaining encumberences. They have however been reduced to 1%, and OpenJDK can run complex applications such as Netbeans, Eclipse, Glassfish, or JBoss.

Status

Supported JDK versions

OpenJDK was initially based only on the JDK 7.0 version of the Java platform.

Since February 15, 2008, there are two separate OpenJDK projects:

* The main OpenJDK project, which is based on the JDK 7.0 version of the Java platform,
* The JDK 6 project, which provide an Open-source version of Java 6.0.

Compiler and Virtual Machine

Sun's Java compiler, javac, and HotSpot (the virtual machine), are now under a GPL license.

Class library

As of October 2007, the parts of the Class library that remain proprietary and closed-source (4% as of May 2007 for OpenJDK 7, and 1% as of April 2008 and OpenJDK 6) are:

* some parts of the audio engine code (connection to underlying audio systems, and some implementations of higher level functionalities, such as a MIDI synthesizer),
* The Javascript plugin (even if the engine itself is open-source).

Since the first May 2007 release, Sun Microsystems has released as Open-source or replaced with Open-source alternatives some of the encumbered code:

* The majority of the audio engine code has been released as Open-source.
* All cryptography classes used in the Class library have been released as Open-source.[24]
* The code that scales and rasterizes fonts has been replaced by FreeType
* The native color management system has been replaced by LittleCMS. There is a pluggable layer in the JDK, so that the commercial version can use the old color management system and OpenJDK can use LittleCMS.
* The anti-aliasing graphics rasterizer code has been replaced by the Open-sourced Pisces renderer used in the phoneME project. This code is fully functional, but still needs some performance enhancements.

IcedTea

Because of the still encumbered components in the Class library, it is not yet possible to build OpenJDK only with free software components. In order to be able to do this before the whole class library is made free, and to be able to bundle OpenJDK in Fedora and other free Linux distributions, a project called IcedTea has been started by Red Hat. It is basically an OpenJDK/GNU Classpath hybrid that can be used to bootstrap OpenJDK using only Free Software.

IcedTea is a software development and integration project launched by Red Hat in June 2007.The goal is to make the OpenJDK software which Sun Microsystems released as free software in 2007 usable without requiring any other software that is not free software. For Red Hat, this would make it possible to add OpenJDK to the Fedora Linux distribution, as well as other distributions.

On November 05, 2007, Red Hat has signed both the Sun Contributor Agreement and the OpenJDK Community TCK License.One of the first benefits of this agreement is tighter alignment with the IcedTea project, which brings together Fedora and JBoss technologies in a Linux environment, IcedTea providing Free Software alternatives for the few remaining proprietary sections in the OpenJDK project.

As of March 2008, the Fedora 9 distribution will be released with OpenJDK 6 instead of IcedTea. Some of the stated reasons for this changes are:

* Sun has replaced most of the encumbrances for which IcedTea was providing replacements (there is still approximately 1% of encumbered code in the class library).
* OpenJDK 6 is a stable branch, whereas OpenJDK 7 is unstable and not expected to ship a stable release until 2009.
* Sun has licensed the OpenJDK trademark for use in Fedora.

As of April 2008, Ubuntu also focuses on their OpenJDK 6 IcedTea, showing less activity on their OpenJDK 7 IcedTea.

Phonon

2008-05-22T05:41:00.000-07:00

Phonon is the cross platform multimedia API for KDE 4. Phonon was created as a solution to several problems commonly faced by unix desktops for multimedia. Phonon itself is not a multimedia framework, but interfaces with existing frameworks such as GStreamer or Xine via backends. Phonon allows all multimedia frameworks it supports to be accessed through a simple API. This prevents problems like frameworks becoming unmaintained, API instability, and KDE depending on a single framework. Phonon is not limited to unix and backends are being developed to support Windows and Mac OS X by Trolltech.

For example, a file can be played in only a few lines of C++ code, an order of magnitude less than required using the old audio framework (aRts).

MediaObject *media = new MediaObject(this);
media->setCurrentSource("/home/username/music/filename.ogg");
media->play();

Phonon reduces redundant and difficult work done by developers, while not having every conceivable multimedia feature it does provide a simple way to perform common functions of media players. Though some developers may require more control over a backend than Phonon can provide.

Features

* Phonon interfaces with various backends with what developers call "engines"; each engine works with one specific backend. Each backend lets Phonon control basic functions like play, pause, and seek. Phonon will also support higher level functions such as how tracks fade into each other.
o Supported backends on Unix-like systems as of 23 April 2008 include xine, Gstreamer, VLC and MPlayer;
o Supported backends under Windows include DirectX, VLC and MPlayer ;
o Supported backends under Mac OS X include Quicktime ;

* Phonon is able to switch multimedia frameworks on the fly. The user is able to switch between frameworks even while listening to music, with only a slight pause during the switch. This change is also system wide, affecting all applications that use Phonon, so changing frameworks will be much easier.

* Using Solid, Phonon will give the users greater control over accessories like headsets, speakers, and microphones. An example was given that you could have a VoIP conversation only be played through your headset, but have all other sounds come out through speakers. Phonon also gives developers much easier access to multimedia hardware like webcams, which Phonon will be able to record from by the release of KDE 4.1.

Trolltech

Trolltech uses Phonon in its Qt 4.4 release to provide cross platform audio/video playback.

Zwiki

2008-02-21T06:04:00.000-08:00

Zwiki

Zwiki is a wiki engine written in Python and based on the Zope web application server. It was developed by Joyful Systems and contributors from around the world, and is free software released under the GNU General Public License.

Zwiki supports a number of wiki markup styles out of the box, including MoinMoin, Structured text, reStructuredText, but allows also to edit pages in LaTeX or wysiwyg HTML. Zwiki can also co-exist with the Plone content management system. The Zope 2 and Zope 3 projects use Zwiki for part of their documentation.

Zwiki also offers email-integrated discussion, an integrated issue tracker, internationalization support, precise access control (using the Zope Application Server's ACL functionality), and many more optional features such as fuzzy urls, automatic page hierarchy, use of external editors, embedded DTML scripts, and RSS feeds for changed and newly created pages.

Storage backend

Due to the use of the Zope application server, Zwiki pages are by default stored in the ZODB object oriented database backend.

TigerWiki

2008-02-21T06:02:00.000-08:00

TigerWiki

TigerWiki was a minimalist system written in PHP using the wiki base to easily build a framework of community sharing. Based on roWiki, it takes its basis while adding several functionalities such as password protection and the advanced management of pages history. Moreover, this free wiki software does not require MySQL to work. It was distributed under GNU General Public License.

The development of TigerWiki was discontinued in September 2007. However, a fork was born shortly afterwards to create WiKiss, the official TigerWiki successor.

PhpWiki

2008-02-21T06:00:00.000-08:00

PhpWiki

PhpWiki is wiki software written in PHP. The first version, by Steve Wainstead, was in December 1999 and was the first Wiki written in PHP to be publicly released.

The first version ran under PHP 3.x and ran on DBM files only. It was a feature-for-feature reimplementation of the original WikiWikiWeb at c2.com.

In early 2000 Arno Hollosi contributed a second database library to run PhpWiki on MySQL; from then on the features and contributions started to pile up, including a templating system, color diffs, rewrites of the rendering engine and much more. Arno was interested in running a wiki for the game Go. http://senseis.xmp.net/?GoWiki

Jeff Dairiki would be the next major contributor, and would soon head the project for the next couple of years. His interest was in Hammond Organs, and runs a wiki for Hammonds: http://www.dairiki.org/HammondWiki/

Reini Urban, Carsten Klapp, and Joel Uckerman are the primary developers today and PhpWiki is actively maintained and developed.

PikiPiki

2008-02-21T05:59:00.000-08:00

PikiPiki

PikiPiki is a wiki engine. It is written in Python by Martin Pool, and licenced under the GNU GPL. PikiPiki is and aims to stay small: the current version is about 580 lines of commented code.

MoinMoin

2008-02-21T05:55:00.000-08:00

MoinMoin

MoinMoin is a wiki engine implemented in Python, initially based on the PikiPiki wiki engine. Distributed under the terms of the GNU General Public License, MoinMoin is free software.

The feature set of fine grained access control, simple user groups, GUI editor, easy install, simple but efficient spam protection, easy theming combined with a simple code base makes it often the wiki of choice for many open source projects (e.g. Apache, Debian, Ubuntu, Fedora) and corporate wikis.

Technical details

MoinMoin's storage mechanism is based on flat files and folders, rather than a database. This makes it easy to manipulate the content in a text editor on the server if need be, including managing revisions if the wiki gets attacked by spammers. A storage abstraction layer is currently being worked on, which will allow the server administrator to select between flat file-storage or a relational database.

MoinMoin supports plugins and can be extended via Macros and Actions. It also uses the idea of separate parsers (e.g. for parsing the wiki syntax) and formatters (e.g. for outputting HTML code) with a SAX-like interface between the two. The idea is that if you want to be able to output DocBook instead of HTML, you only need to write a docbook-formatter that implements the formatter interface, and all parsers that use the interface will automatically be supported.

MoinMoin supports CamelCase linking as well as free links (non-CamelCase linking).

MoinMoin also has extensive support for Access Control Lists (ACL) that greatly increase its usability in a content management system (CMS). It also has GUI editing capabilities.

MoinMoin is able to either use a built-in search engine (rather slow, but no dependencies) or a Xapian based indexed search engine (faster, and can also search old revisions and attached files).

MoinMoin also allows synchronisation of contents from instance to instance via XML-RPC and therefore allows distributed offline editing on a laptop.

Since 1.6.0, MoinMoin supports easy installation in a similar way as the "DesktopEdition" realised for older releases. Also in this release a different markup syntax was introduced, which hasn't been changed much since the early releases.

NTFS-3G

2008-02-19T00:51:00.000-08:00

NTFS-3G

NTFS-3G is an open source, freely available NTFS driver for Linux, Mac OS X, FreeBSD, NetBSD, BeOS and Haiku. It is licensed under the GNU General Public License. It is based on ntfsmount with full directory index operations, and offers "unlimited file creation and deletion".

NTFS-3G was introduced by Szabolcs Szakacsits in July of 2006. The first stable version was released on 2007-02-21 as version 1.0.

Limitations

Unlike the NTFS driver included in the Linux kernel, NTFS-3G supports most operations for writing files: files of any size can be created, modified, renamed, moved, or deleted on NTFS partitions, except compressed and encrypted files. Experimental support to modify access control lists and permissions is available. NTFS partitions are mounted using the Filesystem in Userspace (FUSE) user space file system framework.

Performance

Recent benchmarks show that the driver's and other filesystems' performance are very comparable:

* Comparing JFS, XFS, NTFS-3G and ZFS-FUSE performance
* Benchmarks of 10 filesystems

That said, NTFS-3G is not yet optimized for performance. The focus of the development is still reliability and implementing the missing POSIX functionalities.

History

* Since 2006-10-31, NTFS-3G is a project on its own, no longer part of the Linux-NTFS project.
* On 2007-02-21, Szabolcs Szakacsits announced "the release of the first open source, freely available, stable read/write NTFS driver, NTFS-3G 1.0".

ReiserFS

2008-02-16T23:00:00.000-08:00

ReiserFS

ReiserFS is a general-purpose, journaled computer file system designed and implemented by a team at Namesys led by Hans Reiser. ReiserFS is currently supported on Linux and may be included in other operating systems in the future. Introduced in version 2.4.1 of the Linux kernel, it was the first journaling file system to be included in the standard kernel. ReiserFS is the default file system on the Elive, Xandros, Yoper, Linspire, GoboLinux and Kurumin Linux[citation needed] Linux distributions. ReiserFS was the default file system in Novell's SUSE Linux Enterprise until Novell decided to move to ext3 on October 12, 2006 for future releases. Although it was rumored to be a result of principal author Hans Reiser being charged with the murder of his wife two days earlier, SUSE stated that the timing of the announcement was coincidental and unrelated.

Namesys considers ReiserFS (now occasionally referred to as Reiser3) stable and feature-complete and, with the exception of security updates and critical bug fixes, has thus ceased development on it to concentrate on its successor, Reiser4.

A very extensive website can be found at Namesys describing it, with diagrams and detailed explanations of its algorithms and benchmarks.

Features

At the time of its introduction, ReiserFS offered features then unseen in existing Linux file systems:

* Metadata-only journaling (also block journaling, since Linux 2.6.8), its most-publicised advantage over what was the stock Linux file system at the time, ext2.
* Online resizing (growth only), with an underlying volume manager such as LVM. Since then, Namesys has also provided tools to resize (both grow and shrink) ReiserFS file systems offline.
* Tail packing, a scheme to reduce internal fragmentation. Tail packing, however, can have a significant performance impact. Namesys recommends disabling the feature in performance-critical applications. Reiser4 may have improved this by packing tails where it doesn't hurt performance.

Performance

Compared to ext2 and ext3 in version 2.4 of the Linux kernel, when dealing with files under 4 KiB and with tail packing enabled, ReiserFS is often faster by a factor of 10–15.[citation needed] This is of great benefit in Usenet news spools, HTTP caches, mail delivery systems and other applications where performance with small files is critical.

However, because ReiserFS still uses the Big Kernel Lock (BKL) - a global kernel-wide lock - in some places, it does not scale very well for systems with multiple cores, as the critical code parts are only ever executed by one core at a time.

Criticism

Some directory operations are not synchronous on ReiserFS, which can result in data corruption with applications relying heavily on file-based locks (such as mail transfer agents qmail and Postfix) if the machine halts before it has synchronized the disk.

There are no programs to specifically defragment a ReiserFS file system, although tools have been written to automatically copy the contents of fragmented files hoping that more contiguous blocks of free space can be found. However, Reiser4 will have a repacker that optimizes file fragmentation.

fsck

The tree rebuild process of ReiserFS's fsck has attracted much criticism: If the file system becomes so badly corrupt that its internal tree is unusable, performing a tree rebuild operation may further corrupt existing files or introduce new entries with unexpected contents. But this action is not part of normal operation or a normal file system check and has to be explicitly initiated and confirmed by the administrator.

Nevertheless it is recommended not to store ReiserFS v3 images on a ReiserFS v3 partition (e.g. backups or disk images for emulators) without transforming them to a form that avoids misleading the file system, e.g., by compressing or encrypting. Reformatting an existing ReiserFS v3 partition can also leave behind data that could confuse the rebuild operation and make files from the old system reappear. This also allows malicious users to intentionally store files that will confuse the rebuilder. As the metadata is always in a consistent state after a file system check, corruption here means that contents of files are merged in unexpected ways with the contained file system's metadata. The ReiserFS successor, Reiser4, fixes this problem.

Earlier issues

ReiserFS in versions of the Linux kernel before 2.4.16 were considered unstable by Namesys and not recommended for production use, especially in conjunction with NFS.

Early implementations of ReiserFS (prior to that in Linux 2.6.2) were also susceptible to out-of-order write hazards. For example, files being appended to during a crash gained a tail of garbage upon next mount.[citation needed] But the current journaling implementation in ReiserFS is now on par with that of ext3's "ordered" journaling level.

Design

ReiserFS stores file metadata ("stat items"), directory entries ("directory items"), inode block lists ("indirect items"), and tails of files ("direct items") in a single, combined B+ tree keyed by a universal object ID. Disk blocks allocated to nodes of the tree are "formatted internal blocks". Blocks for leaf nodes (in which items are packed end-to-end) are "formatted leaf blocks". All other blocks are "unformatted blocks" containing file contents. Directory items with too many entries or indirect items which are too long to fit into a node spill over into the right leaf neighbour. Block allocation is tracked by free space bitmaps in fixed locations.

By contrast, ext2 and other Berkeley FFS-like file systems simply use a fixed formula for computing inode locations, hence limiting the number of files they may contain. Most such file systems also store directories as simple lists of entries, which makes directory lookups and updates linear time operations and degrades performance on very large directories. The single B+ tree design in ReiserFS avoids both of these problems due to better scalability properties.

ext3

2008-02-16T22:50:00.000-08:00

ext3

The ext3 or third extended filesystem is a journalled file system that is commonly used by the Linux operating system. It is the default file system for many popular Linux distributions. Stephen Tweedie first revealed that he was working on extending ext2 in a February 1999 kernel mailing list posting and the filesystem was merged with the mainline kernel from 2.4.15 onward.

Advantages

Although its performance (speed) is less attractive than competing linux filesystems such as JFS, ReiserFS and XFS, it does have the significant advantage that it allows in-place upgrades from the ext2 file system without having to back up and restore data as well as requiring lower CPU consumption than ReiserFS and XFS.[4]

The ext3 file system adds, over its predecessor:

* A journal
* Online file system growth

Without these, any ext3 file system is also a valid ext2 file system. This has allowed well-tested and mature file system maintenance utilities for maintaining and repairing ext2 file systems to also be used with ext3 without major changes. The ext2 and ext3 file systems share the same standard set of utilities, e2fsprogs, which includes a fsck tool. The close relationship also makes conversion between the two file systems (both forward to ext3 and backward to ext2) straightforward.

There are three levels of journaling available in the Linux implementation of ext3:

Journal (lowest risk)

Both metadata and file contents are written to the journal before being committed to the main file system. Because the journal is relatively continuous on disk, this can improve performance in some circumstances. In other cases, performance gets worse because the data must be written twice - once to the journal, and once to the main part of the filesystem.

Ordered (medium risk)

Only metadata is journaled; file contents are not, but it's guaranteed that file contents are written to disk before associated metadata is marked as committed in the journal. This is the default on many Linux distributions. If there is a power outage or kernel panic while a file is being written or appended to, the journal will indicate the new file or appended data has not been "committed", so it will be purged by the cleanup process. (This appends and new files have the same level of integrity protection as the "journaled" level.) However, files being overwritten can be corrupted because the original version of the file is not stored. Thus it's possible to end up with a file in an intermediate state between new and old, without enough information to restore either one or the other (the new data never made it to disk completely, and the old data is not stored anywhere). Even worse, the intermediate state might intersperse old and new data, because the order of the write is left up to the disk's hardware.

Writeback (highest risk)

Only metadata is journaled; file contents are not. The contents might be written before or after the journal is updated. As a result, files modified right before a crash can become corrupted. For example, a file being appended to may be marked in the journal as being larger than it actually is, causing garbage at the end. Older versions of files could also appear unexpected after a journal recovery. The lack of syncronicity between data and journal is faster in many cases. XFS,and JFS use this level of journaling, but ensures that any "garbage" due to unwritten data is zeroed out on reboot.

While in some contexts the lack of "modern" filesystem features such as dynamic inode allocation and extents could be considered a disadvantage, in terms of recoverability this gives ext3 a significant advantage over file systems with those features. The file system metadata is all in fixed, well-known locations, and there is some redundancy inherent in the data structures that may allow ext2 and ext3 to be recoverable in the face of significant data corruption, where tree-based file systems may not be recoverable.

Disadvantages

Functionality

Since ext3 aims at being mostly compatible with ext2, many of the on-disk structures are similar to those of ext2. Because of that, ext3 lacks a number of features of more recent designs, such as dynamic allocation of i-nodes and variable block sizes (frags or tails).

ext3 filesystems cannot be fscked while the filesystem is mounted for writing. A dump of the filesystem taken while it is mounted read-write may result in corrupt data within the dump file.

ext3 does not support extents, a feature found in other filesystems such as JFS, ext4 and XFS.

Defragmentation

There is no online ext3 defragmentation tool working on the filesystem level. An offline ext2 defragmenter, e2defrag, exists but requires that the ext3 filesystem be converted back to ext2 first. But depending on the feature bits turned on the filesystem, e2defrag may destroy data; it does not know how to treat many of the newer ext3 features.

There are userspace defragmentation tools like Shake and defrag, which work by copying each file and hoping the newly allocated file was not fragmented. However this only works if the filesystem is reasonably empty, and such filesystems are not usually fragmented. A true defragmentation tool does not exist for ext3.

However, as the Linux System Administrator Guide states, "Modern Linux filesystem(s) keep fragmentation at a minimum by keeping all blocks in a file close together, even if they can't be stored in consecutive sectors. Some filesystems, like ext3, effectively allocate the free block that is nearest to other blocks in a file. Therefore it is not necessary to worry about fragmentation in a Linux system."

Undeletion

Unlike ext2, ext3 zeroes out block pointers in the inodes of deleted files. It does this to simplify read-write access to the filesystem when the journal is being replayed after an unclean mount. This, however, effectively prevents files from being undeleted. The user's only recourse is to grep the hard drive for data known to signal the start and end of the file. This provides slightly more secure deletion than ext2, which can be either an advantage or a disadvantage.

Compression

Support for transparent compression (available as an unofficial patch for ext2) is not available in ext3.

No checksumming in journal

Ext3 does not do checksumming when writing to the journal. If barrier=1 is not enabled as a mount option (in /etc/fstab), and if the hardware is doing out-of-order write caching, one runs the risk of severe filesystem corruption during a crash. (This option is not enabled by default on almost all popular Linux distributions, and thus most distributions are at risk.)

Consider the following scenario: If hard disk writes are done out-of-order (due to modern hard disks caching writes in order to amortize write speeds), it is likely that one will write a commit block of a transaction before the other relevant blocks are written. If a power failure or kernel panic should occur before the other blocks get written, the system will have to be rebooted. Upon reboot, the file system will replay the log as normal, and replay the "winners" (transactions with a commit block, including the invalid transaction above which happened to be tagged with a valid commit block). The unfinished disk write above will thus proceed, but using corrupt journal data. The file system will thus mistakenly overwrite normal data with corrupt data while replaying the journal. If checksums had been used (if the blocks of the "fake winner" transaction were tagged with mutual checksum), the file system could have known better and not replayed the corrupt data onto the disk. As of June 24, 2007, a patch is in the works to fix this problem.

qmail

2008-02-15T02:29:00.000-08:00

qmail

qmail is a mail transfer agent that runs on Unix. It was written by Daniel J. Bernstein as a more secure replacement for the popular Sendmail program.

Features

Security

When first published, qmail was the first security-aware mail transport agent; since then, other security-aware MTA's have been published. The most popular predecessor to qmail, Sendmail, was not designed with security as a goal, and as a result has been a perennial target for attackers. In contrast to sendmail, qmail has a modular architecture composed of mutually untrusting components; for instance, the SMTP listener component of qmail runs with different credentials than the queue manager, or the SMTP sender. qmail was also implemented with a security-aware replacement to the C standard library, and as a result has not been vulnerable to stack and heap overflows, format string attacks, or temporary file race conditions.

Performance

When it was released, qmail was significantly faster than Sendmail, particularly for bulk mail tasks such as mailing list servers. qmail was originally designed as a way for managing large mailing lists.

Simplicity

Prior to qmail, the most popular Internet mail server was Sendmail. Sendmail configuration had been notoriously complex, involving one of the most complicated configuration file formats facing Unix systems administrators. In contrast, qmail was configured using a series of small flat files. For common configurations, in many circumstances, qmail was significantly easier to configure and deploy.

Innovations

qmail encourages the use of several innovations in mail (some originated by Bernstein, others not):

Maildir

Bernstein invented the Maildir format for qmail, which splits individual email messages into separate files. Unlike the de facto standard Mbox format, which stored all messages in a single file, Maildir avoids many locking and concurrency problems, and can safely be provisioned over NFS. qmail also delivers to Mbox mailboxes.

Wildcard mailboxes

qmail introduced the concept of user-controlled wildcards. Out of the box, mail addressed to "user-wildcard" on qmail hosts is delivered to separate mailboxes, allowing users to publish multiple mail addresses for mailing lists and spam management.

qmail also introduces the QMTP and QMQP protocols.

Modularity

qmail is nearly a completely modular system in which each major function is separated from the other major functions. It is easy to replace any part of the Qmail system with a different module as long as the new module retains the same interface as the original.

Controversy

qmail was designed as a pointed response to Sendmail, an extremely popular and somewhat beloved piece of Unix software. Author Bernstein was not shy about pointing out the deficiencies in Sendmail's design and the superior characteristics of qmail, nor did he take pains to replicate Sendmail's behavior, which at the time was the de facto standard for Internet mail delivery. As a result, qmail came under unusually intense scrutiny.

Security reward and Georgi Guninski's vulnerability

Bernstein offered a US$500 reward for the first person to publish a verifiable security hole in the latest version of the software.

In 2005, security researcher Georgi Guninski found an integer overflow in qmail. On 64-bit platforms, in certain configurations of disputed realism (including absence of resource limits and unusually large amounts of available virtual memory), the delivery of huge amounts of data to certain qmail components may allow remote code execution. Bernstein disputes that this is a practical attack, arguing that no real-world deployment of qmail would be susceptible. Configuration of resource limits for qmail components mitigates the vulnerability.

On November 1, 2007, Bernstein raised the reward to US$1000. At a slide presentation the following day, Bernstein stated that there were 4 "known bugs" in the ten year old qmail-1.03, none of which were "security holes." He characterized the bug found by Guniski as a "potential overflow of an unchecked counter." "Fortunately, counter growth was limited by memory and thus by configuration, but this was pure luck."

Frequency of updates

Unlike competitors Postfix and Sendmail, the core qmail package has not been updated for many years New features are provided by third party patches, such as net-qmail. This is a benefit for some users, from not needing to apply patches continuously, and a liability for other users, particularly those who rely on authentication mechanisms that post-date qmail.

Standards compliance

qmail was designed to replace Sendmail, but does not behave exactly as Sendmail did in all situations. In some cases, these differences in behavior have become grounds for criticism. For instance, qmail's approach to bounce messages (a format called QSBMF) differs from that recommended by the IETF in RFC 1894. Furthermore, some qmail features have been criticized for introducing mail forwarding complications; for instance, qmail's "wildcard" delivery mechanism and security design prevents it from rejecting messages to nonexistent senders during SMTP transactions. In the past, these differences may have made qmail behave differently when abused as a spam relay, though modern spam delivery techniques are less influenced by bounce behavior.

Despite these concerns, qmail is among the five most popular Unix mail servers, forwarding a significant fraction of all of the email on the Internet.

Copyright status

qmail was released to the public domain in November of 2007. Formerly, qmail was license-free software, which granted permission for distribution in source form or in pre-compiled form (a "var-qmail package") only if certain restrictions were met, primarily involving compatibility.

qmail is the only broadly deployed MTA in the public domain.

Sendmail

2008-02-15T02:26:00.000-08:00

Sendmail

Sendmail is a mail transfer agent (MTA) that is a well-known project of the open source, free software and Unix communities, which is distributed both as free software and proprietary software.

History and use

A descendant of the original ARPANET delivermail application, Sendmail is a remarkably flexible program, supporting many kinds of mail transfer and delivery including the overwhelmingly popular SMTP. The original version of Sendmail was written by Eric Allman in the early 1980s at UC Berkeley, who had also written delivermail previously. Delivermail was shipped in 1979 with 4.0 and 4.1 BSD. Sendmail was shipped with BSD 4.1c in 1983 (the first BSD version to include TCP/IP).

Sendmail remains the most popular MTA on the Internet. Its popularity is due in part to its position as the standard MTA under most variants of the Unix operating system. According to latest D. J. Bernstein SMTP survey, as of November 2001 approximately 42% of the publicly reachable mail servers on the Internet were running Sendmail. More recent surveys have suggested a decline, with 29.4% of mail servers in August 2007 detected as running Sendmail in a study performed by E-Soft, Inc. Sendmail is trailed by Microsoft Exchange Server, Exim, and Postfix, these four being the only mail servers with more than 10% of the installed base.

As Sendmail is a complex package with a great deal of functionality, it can be difficult for an inexperienced system administrator to configure. Documentation of the Sendmail system has not always kept pace with changes to the administrative interfaces; despite the availability of macro-based configuration tools, many support websites instruct administrators to directly modify configuration files that should instead be managed by administrative tools. The failure of vendors to update their support materials contributes to the perception of Sendmail as a difficult-to-configure package[citation needed].

The complexity of Sendmail does provide benefits, in the form of flexibility and scalability. Sendmail supports a variety of mail transfer protocols, including SMTP, ESMTP, DECnet's mail11, HylaFax, QuickPage and UUCP. Additionally, Sendmail v8.12 as of September 2001 introduced support for milters - external mail filtering programs that can participate in each step of the SMTP conversation.

Security

Sendmail originated in the early days of the modern Internet, an era when security was not a primary consideration in the development of network software. Early versions of Sendmail suffered from a number of security vulnerabilities that have been corrected over the years.

Sendmail itself incorporated a certain amount of privilege separation in order to avoid exposure to security issues. Current versions of Sendmail, like other modern MTAs, incorporate a number of security improvements and optional features that can be configured to improve security and help prevent abuse.

Sendmail X / MeTA1

The next generation of Sendmail was initially called Sendmail X (previously it was called Sendmail 9, but is not an evolution of the Sendmail version 8 code base). However, the development of Sendmail X was stopped in favor of a new project called MeTA1.

The first release of Sendmail X (smX-0.0.0.0) was made available on October 30 2005. The final release was smX-1.0.PreAlpha7.0., released on May 20 2006 under the same license used by Sendmail 8.

Development on MeTA1 continues, with the released code at the pre-alpha stage as of January 2008.

Helix Player

2008-02-13T00:13:00.000-08:00

Helix Player

Helix is a project to produce software that can play audio and video media in various formats, aid in producing such media, and serve them over a network. It is intended as a largely free and open source digital media framework that runs on numerous operating systems and processors (including mobile phones) and was started by RealNetworks which has contributed much of the code.

Helix DNA Client is the multi-platform multi-format media playback engine. Helix Player is a media player that runs on Linux, Solaris, Symbian and FreeBSD and is built on top of Helix DNA Client. Helix Producer is an application that can aid in the production of media files, and Helix DNA Server can stream media files over a network.

Licenses

The code is released in binary and source code form under various licenses, notably the proprietary RealNetworks Community Source License and the free and open source software RealNetworks Public Source License. Additionally, the Helix DNA Client and the Helix Player are licensed under the popular GNU General Public License (GPL) free and open source license.

Use of the RDT, the default proprietary Real data transport, and of the RealVideo and RealAudio codecs requires binary components distributed under the Helix DNA Technology Binary Research Use License.

Helix DNA Client

Helix DNA Client powers many digital media applications, including RealPlayer for Windows, MacOS and Linux (since version 10), RealPlayer Mobile, and Helix Player. It is used on Nokia, Motorola, Samsung and Sony Ericsson mobile phones. According to https://helixcommunity.org, 125 million mobile phones with the Helix client have been shipped since 2006. It is also being used in embedded devices like the Maemo environment from Nokia, which is found on the Nokia 770 Internet Tablet. Cingular Video is also based on the framework. Other projects that use the Helix framework include RealNetwork's Rhapsody online music service, the Banshee and Amarok music players, and MediaReady 4000.

Another project that is taking advantage of the Helix DNA Client is the One Laptop Per Child project. A group of developers from the Open Source Lab are currently working on a media player API for the project, and will continue on using other Helix technologies to create applications for content creation and content collaboration.

Helix DNA client contains support for the following media formats:

* Audio formats: Vorbis, .au
* Video formats: Theora, AVI
* Description formats: SMIL, SDP
* Image formats: JPEG, GIF, PNG
* Protocols: RTSP, RTP, HTTP, Multicast, RDT

Helix DNA Server

The Helix DNA Server, first released on 22 January, 2003, supports streaming RealVideo, RealAudio or MP3 to any device or application that supports the HTTP or RTSP streaming protocols.

Wikia

2008-02-13T00:01:00.000-08:00

Wikia

Wikia (originally Wikicities) is a selective free web hosting service for wikis (or wiki farm) operated by Wikia, Inc., a for-profit Delaware company founded in late 2004.

Wikia particularly targets communities, both those established offline and those with a purely online following. Wikia is free of charge for readers and editors and licenses user-provided content under the GNU Free Documentation License or, in the case of Memory Alpha (CC by-sa) and Uncyclopedia (CC by-nc-sa), a Creative Commons license. The wiki software used is MediaWiki.

Wikia was founded by Jimmy Wales, Chairman Emeritus of the Wikimedia Foundation, and Angela Beesley, who serves on the Communications Committee of the Foundation and chairs its Advisory Board.

History

Wikia changed its name from Wikicities on March 27, 2006, saying that "the name Wikicities has often caused confusion, with many people believing it was a site for city guides rather than wikis about any topic." Following this change, Wikia announced that it had received US$4 million in venture capital from Bessemer Venture Partners. Amazon.com has invested US$10 million in Series B funding. As a result, senior VP of business development Jeff Blackburn joined the company board.

In November 2006, Wikia claimed to have spent only $5.74 on marketing, while generating 40 to 50 million page views. Certain Wikia projects have independently spent money on advertising. The company spent $2 million to purchase ArmchairGM, a previously independently hosted site on the MediaWiki software.

Topics and wikis

Wikia covers a broad range of topics; most widely scoped community projects are accepted,[citation needed] with the exception of ideas that compete with the Wikimedia Foundation's projects,[citation needed] which the Wikia founders are heavily involved in. Wikia requires all content to be licensed under one of many free content licenses, such as the Creative Commons Attribution and Attribution-Sharealike licenses or the GNU Free Documentation License.

The project announced the creation of its one hundredth wiki on February 3, 2005. As of July 2007, it had over 3,000 wikis in over 50 languages.

As of February, 2008, its Alexa traffic ranking was about 400 (Uncyclopedia, Memory Alpha and WoWWiki, three of their most popular wikis, are not included in this figure as they have separate domain names). The largest source of Wikia.com traffic is its hosting of Wookieepedia, the Star Wars fan information wiki, accounting for 17% of Wikia traffic as of May 2007. The Wikia-hosted World of Warcraft Wiki gets even more traffic on a separate domain name. The veracity of Alexa information must be considered carefully, as rankings rely upon sampling methods that are highly susceptible to inaccuracy, possibly resulting in much greater or much smaller traffic estimates than might actually be achieved.

Some domain names that are not included in the wikia.com figure stem from wikis that were founded separately from Wikia and incorporated into Wikia later. In the case of GuildWiki, this incorporation involved Wikia paying money and/or stock options to the previous owner of the domain name used for these wikis.

Software

Wikia uses MediaWiki software on GNU/Linux servers, and claims to provide both technical and social support for all aspects of running a wiki community.

Search engines

Wikiasari

Wikia Inc. initially proposed creating a copyleft search engine; the software (but not the site) was named "Wikiasari" by a November 2004 naming contest. The proposal became inactive as of 2005.

Search Wikia

The "public alpha" of Wikia Search web search engine was launched on January 7, 2008. This roll-out version of the search interface was roundly panned by reviewers in technology media.

Company

Wikia, Inc. is a company based in San Mateo, California, U.S. The company was originally incorporated in Florida in December 2004 and re-incorporated in Delaware as Wikia, Inc. on 10 January 2006. Angela Beesley has served since the beginning as Wikia's Vice-President of Community Relations. Gil Penchina, a former vice president and general manager at eBay, was hired as CEO on June 5, 2006. Gil had previously been one of a group of angel investors in the company. Michael E. Davis, a former business partner of Wales who served for years as a founding member of the Wikimedia Foundation board and was that organization's Treasurer, was named Treasurer and Secretary of Wikia in January 2006.

Wikia has some technical staff in the USA, but has also opened an office in Poznań, Poland in 2006. Explaining his choice of location, Wales commented "It's about reasonable salaries and high quality. You can find cheaper programmers in other parts of the world, but the quality's not there!"

Wikia and Wikimedia

In 2006, the Wikimedia Foundation shared hosting and bandwidth costs with Wikia, Inc. The Wikimedia Foundation received some donated office space from Wikia Inc. during the fiscal year ending June 30, 2006." Through 2007, the Foundation was owed $6,000USD by Wikia. Through June 2007, two members of the Foundation's Board of Directors also served as employees, officers, or directors of Wikia, Inc.

Since the end of 2006, the offices of the two organizations are located in different cities and with completely different management teams.

KGPG

2008-02-12T01:52:00.000-08:00

KGPG

KGPG is a KDE graphical frontend for GnuPG, which includes a key management window and an editor. Users can easily create cryptographic keys, and write, encrypt, decrypt, sign, or verify messages.

Through integration with the Konqueror browser, users can easily encrypt files by right-clicking and choosing Actions > Encrypt File. Left-clicking on an encrypted file in Konqueror will prompt the user for a password to decrypt the file. You can make public or private keys, and can export/import keys. A user can sign the keys, and set an expiration date.