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.
OpenRa does so much, it's amazing that this golden age of RTS that was the command and conquer series is still so much fun. And with the OpenRa server browser, balance tweaks, performance optimisation, command and conquer has just gotten better.
In short, Command and Conquer is still the golden RTS series it always was, just slightly better, thanks to all the contributers of OpenRa splendid job.