This today from a person returning to D&D and rediscovering the enchantment again of creation:

"I  am really keen to try out the megadungeon for an online gaming group.  We use Fantasy Grounds II as a virtual tabletop and Castles & Crusades for rules.  Once we've got things kicked off, I'd like to come back to you for [Dungeon] Set #2.  Of course, I will also be interested to check out future related products.  This line of materials is exactly the kind of thing I've been looking for."...

"I stopped gaming in the late 80s and 2e and 3e passed me by.  It was only when 4e was published and the guys wanted to get back together with their sons joining in that I thought of D&D.  The OSR has rekindled my interest in RPGs in general and older editions of D&D in particular.  What you appear to be doing at Pied Piper will help relative novices like me reignite our imaginations."...

I would like to add this as an answer to the above and as a further inspiration from us to creative and imaginative DMs everywhere--from OD&D's Forward by EGG, written just a tiny bit over 36 years ago to the day:

"ONCE UPON A TIME, long, long ago there was a little group known as the Castle and Crusade Society. Their fantasy rules were published, and to this writer's knowledge, brought about much of the current interest in fantasy wargaming. For a time the group grew and prospered, and Dave Arneson decided to begin a medieval fantasy campaign game for his active Twin Cities club. From the map of the "land" of the "Great Kingdom" and environs — the territory of the C & C Society — Dave located a nice bog wherein to nest the weird enclave of "Blackmoor", a spot between the "Great Kingdom" and the fearsome "Egg of Coot". From the CHAINMAIL fantasy rules he drew ideas for a far more complex and exciting game, and thus began a campaign which still thrives as of this writing! In due course the news reached my ears, and the result is what you have in your hands at this moment. While the C & C Society is no longer, its spirit lives on, and we believe that all wargamers who are interested in the medieval period, not just fantasy buffs, will enjoy playing DUNGEONS and DRAGONS. Its possibilities go far beyond any previous offerings anywhere!
While it is possible to play a single game, unrelated to any other game events past or future, it is the campaign for which these rules are designed. It is relatively simple to set up a fantasy campaign, and better still, it will cost almost nothing. In fact you will not even need miniature figures, although their occasional employment is recommended for real spectacle when battles are fought. A quick glance at the Equipment section of this booklet will reveal just how little is required. The most extensive requirement is time. The campaign referee will have to have sufficient time to meet the demands of his players, he will have to devote a number of hours to laying out the maps of his "dungeons" and upper terrain before the affair begins. The third booklet of this set will be of great help in this respect, for a number of helpful suggestions regarding how to accomplish it all have been given in order to help you accomplish the task with a minimum of time and effort. There should be no want of players, for there is unquestionably a fascination in this fantasy game — evidenced even by those who could not by any stretch of the imagination be termed ardent wargamers. The longevity of existing campaigns (notably "Blackmoor" in the Twin Cities and "Greyhawk" in Lake Geneva) and the demand for these rules from people outside these campaigns point towards a fantastic future. Tactical Studies Rules believes that of all forms of wargaming, fantasy will soon become the major contender for first place. The section of this booklet entitled Scope will provide an idea of just how many possibilities are inherent in DUNGEONS and DRAGONS.
These rules are strictly fantasy. Those wargamers who lack imagination, those who don't care for Burroughs' Martian adventures where John Carter is groping through black pits, who feel no thrill upon reading Howard's Conan saga, who do not enjoy the de Camp & Pratt fantasies or Fritz Leiber's Fafhrd and the Gray Mouser pitting their swords against evil sorceries will not be likely to find DUNGEONS and DRAGONS to their taste. But those whose imaginations know no bounds will find that these rules are the answer to their prayers. With this last bit of advice we invite you to read on and enjoy a "world" where the fantastic is fact and magic really works!
E. Gary Gygax 1 November 1973
Tactical Studies Rules Editor Lake Geneva, Wisconsin"