Allegro 5: A game programming library

Allegro is the Italian for «quick, lively, bright». It is also a recursive acronym which stands for «Allegro Low LEvel Game ROutines». Allegro was started by Shawn Hargreaves in the mid-90's but has since received contributions from hundreds of people over the net.

 Allegro 5

Allegro 5 is the latest major revision of the library, designed to take advantage of modern hardware (e.g. hardware acceleration using 3D cards) and operating systems. Although it is not backwards compatible with earlier versions, it still occupies the same niche and retains a familiar style.
Allegro 5.0 supports the following platforms:

•Unix/Linux
•Windows (MSVC, MinGW)
•MacOS X
•iPhone
Allegro 5.1 also adds support for:
•Android

You can see the functionality Allegro provides by browsing the online reference manual.
Allegro only supports 2D graphics primitives natively, but it is perfectly reasonable to use Allegro alongside a 3D API (e.g. OpenGL, Direct3D, and higher level libraries), while Allegro handles the other tasks. Allegro is also designed to be modular; e.g. if you prefer, you can substitute another audio library.
http://liballeg.org/