Teen Programmers Unite was formed in the summer of 1996 as the result of a post to the USENET newsgroup rec.games.programmer. The first mission description given there was to "form a mailing list ... share info, and maybe, heaven forbid, create a game." A short-lived mailing list was created, but most of the action switched to a now-defunct web site maintained by DavidKitchin, the first "admin" of TPU. It featured an obscene mass mailto link including all member e-mail addresses instead of a regular mailing list. By the end of the year, we were settled into an IRC channel, the first #tpu, on a small Filipino server named irc.skyinet.net.
The low-tech solutions to problems that were being used started to get annoying, and so AdamChlipala volunteered to switch thing after thing to custom developed CGI scripts. He hosted the first message boards as one forum among several on his personal site, Conspiracies, Intrigue, and Donkeys. He created a semi-automated sign-up process that automatically generated a horrendous mass mailto link, instead of forcing a person to update it by hand! A short-lived Yahoo!-modelled search engine appeared as well. The main web site continued to evolve, and the first group of admins was created: LukeChao, AdamChlipala, JarrodDavis, and DavidKitchin.
There were many interesting projects and other goings-on during these early years. We quickly switched our IRC channel to EFNet, the largest IRC network. The DJGPP Interest Group started the CodenameFlash project, a doomed effort to create a side-scrolling action game. Some realtime strategy game projects that weren't associated particularly with TPU but that a lot of members involved themselves with were ProjectArmageddon (archived web site) and BlastedWastes. We had an interpreter contest, with prizes donated by Microsoft (!), won by the people who organized it. There was a Linux/Unix Interest Group and an effort to create a TPU Linux distribution. Quite a crew built up around the IRC channel, initially attracted by weekly meetings and discussions on these and other projects. We channel regulars developed a trademark mythos revolving, oddly enough, around goats. Flaming goats and Muffy the Magic Goat figured prominently.
At the end of 1997, we bought the tpu.org domain, after using the domain tpu.ml.org for a while. The switch from the traditional web site hosted via a family ISP account was triggered by the sudden (to most of us) cancellation of that account. We formed a group of about 8 "admins" assigned to various areas of keeping the group running. One new undertaking was to publish a regular e-mail newsletter, The Teen Programmer's Journal. The page underwent a few funky redesigns which are unfortunately not archived. AdamChlipala developed a variety of versions of CGI software to run the site, and new features were constantly appearing and going away a few months later.
At the end of 1998, AdamChlipala wasn't too happy with the way things were going. A lot of the old enthusiasm of participants was gone, and the web site forums were used mostly by newbies. As a result, he decided to refocus efforts into a general programming resource site called devlocus.org. #tpu kept up moving along as always, with its lively group of friends drifting further and further away from the original topic that brought them together. The TPU web site was made a part of devlocus. Somewhere in there, AdamChlipala also decided it would be a good idea to change the "Unite" in our name to "Union," to sound more "professional." He made a lot of unpopular decisions around this time, in fact. 
To somewhat rectify the bizarre shift of TPU from social gathering to resource site, a kinder, gentler plan was attempted briefly, based around a minimalist web site, IRC channel, and mailing list.
This didn't really work out. AdamChlipala felt like "moving on" to things involving groups he wouldn't officially grow out of within the year and wanted to turn TPU over to real teenagers. He transferred the domain to GarethOwen, who started a new web site with yet another custom-written CGI site engine. There was a lot of enthusiasm here, but the forums, yet again about the only feature of the web site used, became more and more dominated by talk not related to programming, and the programming talk became more and more dominated by simple "newbie questions." AdamChlipala had been working on a Java servlet based multi-web site engine based around the TeaServlet. He wanted to take another try at TPU, in a "last ditch effort" to return it to its former glory before he turned it over to others who could run it in that spirit. About a year after the previous domain transfer, tpu.org was transferred back to Adam, and a new TPU web site using the new engine appeared.
Things have largely continued uneventfully since then, with various failed efforts to liven up interest and increase member participation. We are moving in two main directions now with respect to TPU's future.
First, we are switching it to using this Wiki. What could be more conducive to participation than the open model of a Wiki? Besides, TPU has always been (at least ideally) about the people and helping them communicate, and IRC has always been the most successful way of doing that. #tpu will still be around, the same as ever.
Secondly, we are questioning the value of running an organization aimed only at teenagers. Is that really the main essence of what made TPU so great in its early years? One aspect suggested at the beginning, in replies to the USENET post that started it all, is that it might be the inexperience of members rather than early age that matters. We do plan to make helping people learn programming from the ground up a big part of our mission. However, a lot of us had clearly progressed beyond novice-level ability, even as teenagers, so we don't want to have only a "beginners' club." The real thing that held us together as a common interest, the thing that was so natural that we didn't realize it at the time, was that we coded for fun.
This is the motivation for creating the new Fellowship of Hobbyist Programmers. We hope it can be everything TPU was and more. It's unclear how the old TPU tradition should fit into this. We have a 3-letter second-level domain name in one of the original TLD's, after all! Why put it to waste? One possibility is to keep the #tpu channel around for young FHP participants, since it's hard to come up with a place other than in simple social interactions where it is remotely possible that age segragation is beneficial. Only time will tell how it all works out. The truth is that the "we" used in these last paragraphs really still means AdamChlipala. He's screwed up with TPU-related decisions in the past, but he hopes this one will work out.
On July 13, 2003, www.tpu.org was set to redirect to TeenProgrammersUnite on this wiki, and a static snapshot of the old TPU site relegated to http://old.tpu.org/.
On January 9th, 2004, www.tpu.org pointed to a new site established by GianPerrone.