Return to Castle Wolfenstein: Enemy Territory (RTCW:ET or ET)is one of a few games that I regularly play in the past 10 years. Well, I have not been playing ET using my own account for the past 13 months because the binaries are not fully compatible with OS X Mavericks, starting with the Developer Preview 1.
Enemy Territory: Legacy is:
Open-source team based FPS game compatible with Wolfenstein: Enemy Territory™
Shortly after I am now back on the game. My colleagues and I can be found at ETForever.com.