TrueCombat: Elite is an add-on for RtCW: Enemy Territory, and both are free as you can get. No limitations, no ads, just sheer fun. TC: Elite pretty much looks like Counter Strike, but that cannot change the fact that the game is highly addictive.
After six months of developent, an update has been released - and it brings shedload of features. Version 0.49 includes HDR lighting, massively updated graphics, new game modes and reprogrammed weapons for higher realism. The game is all about realistic movements and weapon behaviour. After playing it, I have to admit that it's really mind-blowing when it comes to what enthusiasts can make from a decent game engine. And watching HDR implemented in Quake III Team Arena engine seriously speaks of the level of commitment from the guys
True Combat Elite :: An Enemy Territory Modification
3D Gamers :: Game Listing :: Wolfenstein: Enemy Territory Downloads
Source : Free HDR game available for download