source code was released in the 2003 leak, the game was worked on by Team gabeN but their work has yet to be released. but the TFI Team are the newest team to work on it. (This Project is no longer in active development.)
Team GabeN's so called "X-Mas build" of their TF2 based on the original Valve files that were leaked in 2003. This download is an original build fixed and modified by the Project Beta team.