TMO (last version was 2.5) was put together by a fellow with a username of "ducimus", starting years ago. He added some ships and planes from other modders, and did some tweaking of the Campaign files, but mostly changed the configuration of the Artificial Intelligence settings in the game, making several aspects of the game more difficult.
FotRS was a similar endeavor by AOTD_MadMax. He started with ducimus' TMO v1.7, and added quite a few ships and planes to that. His team also tweaked the Campaign files and changed the AI. In some areas of the game, FotRS is actually more difficult that TMO.
FotRSU (the "U" is for "Ultimate") is our team's attempt to update FotRS, combining all the versions of it to include all of the ships and planes from AOTD_MadMax (he would drop and add for each version). We still have to work on the AI, since they are literally a bit too "killer", though some like it that way... and Rockin Robbins is the team leader
