Category: games, real-time strategy
Descripton: Widelands is an open source (GPLed) real-time strategy game. It is built upon the SDL and other open source libraries and is (and will always be) under heavy development. If you knew Settlers I & II™ (© Bluebyte), then you already have a rough idea what Widelands is all about because Widelands is heavily inspired by those two games.
I know there is a post for this, but the developer went inactive before he could finish it.