One of the first sites to do this back in 09 I think was Sodar Island Forums which may not sound like much but it was a very active forum and useful for getting TTTE models for Train Simulator I think the Trainz series as people were doing their own models of the series at the time and lots of fanfiction.etc. But it was creepy the amount of authoritarian required just to even VIEW the damn page and I think they censored the hell out of people.