Open-Source reimplementation of Westwood’s Command & Conquer: Red Alert game engine, updated to use the hardware acceleration of modern video cards using OpenGL and OpenAL for sound playback. It runs natively on Windows, Linux and Mac OS X. The game was designed with modifiability in mind, but is not identical to the original. Campaigns and mods made for the legacy game won't work out of the box.
I always liked the C&C series - but unfortunately the multiplayer part was often very very unstable. With OpenRA I'm now even able to play this on my beloved Linux with my friends. I really love what they made with RA.