Known History:
According to iammingy, MarvelMods originated in 2006 from a board over at GameFAQs. It all started in the board for X-Men Legends 2, then migrated to the Marvel: Ultimate Alliance board when MUA was released. A member named THX eventually announced that he would host a forum for the modders, and everyone migrated to this site and MarvelMods was born. iammingy himself, though a member, was not a modder until a bit later, when he began releasing skins.
According to B.L.A.W, one of our most prolific Admins, he didn't actually join until he wanted info on modding. He did, however, check the GameFAQs board often.
idrinkdrpepper, a well-known moderator, said this:
I was a member of a forum called "Haven of Apocalypse" (along with Tetragene) that was following the X-men Legends series, and I was told about someone on GameFAQ that had hex-edited the save file so that they could play as Archangel. So, I went to the GameFAQ board to see how to do that (my GameFAQ screenname was nightcrawler329). I think this was late October 2005. Once I learned how to hex-edit the save file (very easy), I uploaded a video of it to youtube. Actually, I created my youtube account specifically for that purpose.
The community of modders at GameFAQ was small at that point. We were pretty much just poking around the various files using a hex editor and seeing which ones could be swapped and edited. I remember Tetragene (who was also a member of the Haven of Apocalypse Forum) and I were editing the Effects files and trying to change the names of the characters.
I think a few months later, I had figured out how to edit the skin files using Texture Finder. Since I am not a programmer, the process of editing a single skin file was a painstaking process. I remember Tetragene, Kinstryfe, Youngblood0000, and Darkmythology had sent me some edited texture bitmaps that they wanted me to insert into the skin file for them. I think I did a few of those, but then I wrote up detailed instructions on how to use Texture Finder + Hex Editor to make custom skins. I also compiled a short instructional document about how to hex edit your X-men Legends II game. Youngblood000, helped with that. He also created a download directory of all of the customized skins that people created. As a matter of fact, Youndblood0000's web site is still up http://thegamersjournal.com/rpg/pc/xmenlegends2/
At this point, I think the modding community was still active in making more and more customized skins, but I took a break from it in anticipation of the upcoming Marvel Ultimate Alliance game. When MUA came out, I went back to the GameFAQ boards to see if people were modding MUA. I remember Noelemahc was kind of the person running things, along with thetommyboy2002, blizz, and darkmythology. I think they had identified that the herostat file as the one which governed the playable character roster. They were also able to unlock Colossus and Moonknight by transferring some files from the console version (I believe?).
I started getting back into modding by trying to decode the herostat file. The issue was that the only tool I had was the hex editor, and when you open a .engb file in hex editor, you see a bunch of unintelligible hex strings along with some words and numbers. Eventually, I figured out how to parse these files. But, since I am not a programmer, I did it all by hand (translating one hex string at a time). Thankfully, a user named nba2kstuff came along. I described to him the method of how to parse .engb files and he created an awesome program that could edit them. I think it was around this time that THX started marvelmods.com.
nba2kstuff also created a program that automated the skin-editing method, so that it no longer had to be done via hex editor. So, I do think nba2kstuff deserves credit for getting the ball rolling, because his editing software really opened up a world of modding possibilities.
Known Admins:
THX - began the site in 2006
B.L.A.W - joined in 2007
nodoubt_jr - joined in 2007
Teancum - rejoined as a member in 2011, previously an admin since at least 2007.
Known Moderators:
BliZZ - joined in 2006, was originally an Admin
thetommyboy2002 - joined in 2006
idrinkdrpepper - joined in 2006
darkmythology - joined in 2006
Noelemahc - joined in 2006
Cates - joined in 2007
Dihan - joined in 2008
Nowhere Man - joined in 2008
whiteking - joined in 2008
DeeDooo - joined in 2009
midnightphoenix123 - joined in 2010
Known Marvel Modders: (NOTE: These people are given the title of Marvel Modder for being very prolific modders. They also are given access to a private section of the forum, and have the power to lock/unlock topics. Technically anyone who's made mods can be considered a Marvel Modder.)
iammingy - joined in 2006
cvc - joined in 2006
fluid_static - joined in 2006
boreman - joined in 2006
matt710 - joined in 2007
Gevth - joined in 2007
krum4o - joined in 2007
Norrin Radd - joined in 2007
shafcrawler - joined in 2007
Dark_Mark - joined in 2007
Volsung - joined in 2007
DJay Saint (formerly Burning Rage) - joined in 2007
Tetragene - joined in 2007
мaгvel wатcheг - joined in 2008
Scabbia - joined in 2008
MarvelFan12345 - joined in 2009
aventureiromax - joined in 2009
Tien shinhan (formerly Broly- The Legendary Super Saiyan) - joined in 2009
fox456 - joined in 2009
mj fan - joined in 2009
edward - joined in 2010
UltimateVeNoM - joined in 2010
Me - joined in 2010
nuhverah - joined in 2010
SuperNatural-Witch - joined in 2010
MUALover - joined in 2010
Harpua1982 - joined in 2011
sbarth13 - joined in 2011
Tony_Stark (formerly Hyperman360)

- joined in 2012
Odinson012 - joined in 2012
Outsider - joined in 2013
Note: As I get more history, I'll put it up here. If you have anything to add, or if you are a member of one of these groups and you're not listed, or I got something wrong, please post in the thread so I can update this.
Original Post:
You know, I've been wondering... how exactly did MarvelMods come to be? Like who was the original first member/admin, and stuff like that.