It was in August of 2010 that id Software open-sourced Enemy Territory along with Return To Castle Wolfenstein. In writing yesterday about XReaL and OpenWolf game engines that do have compatibility with Enemy Territory, there were interesting comments within the forums.
One of those commenting on the lack of activity on XReaL/OpenWolf was Jan Simek, the founder of ET: Legacy. Jan describes this project as "based on the open-sourced Wolfenstein: Enemy Territory idTech 3 code. Unlike OpenWolf and ET:Xreal we don't have a shiny new renderer yet, but we have been working hard in the past six months to backport ioquake3’s bug and security fixes and clean up the source code. Last time I did line count, code was 33% lighter than vanilla GPL release and we have removed even more garbage since then. Most importantly ET:L is compatible with W:ET 2.60b, so players (and there still are many) can upgrade and keep playing on their favourite servers."
Among the changes within the ET: Legacy code-base over that of id's is a client based upon SDL, translation support, various bug and security fixes, new cvars/functions, improved Linux client sound, Ogg Vorbis client support, speed optimizations, and various other changes. For modding there is Lua scripting support, Omni-Bot support, and much more. ET: Legacy is also running on BSD and even AROS (the AROS Research Operating System).
For those wishing to learn more about this open-source project worthy of being mentioned, visit ETLegacy.com. ET: Legacy is actively developed on GitHub with the latest commits just being hours old at the time of writing.