ClanLib delivers a platform independent interface to write games with. If a
game is written with ClanLib, it should be possible to compile the game under
any platform (supported by ClanLib, that is) without changes in the application
source code.

But ClanLib is not just a wrapper library, providing an common interface to
low level libraries such as DirectX, Svgalib, X11, GGI, etc. While platform
independency is ClanLib's primary goal, it also tries to be a service-minded
game SDK. In other words, authors have put great effort in to designing the API,
to ensure ClanLib's easy of use - while maintaining it's power.

WWW: http://www.clanlib.org/