Allegro
 
Game programming library

Website: http://alleg.sourceforge.net/index.html
Platforms supported: Win32, Linux, DOS
Headers to include: allegro.bi (Allegro 4) or allegro5/allegro.bi (Allegro 5)
Header version: 4.4.2, 5.0.11
Example Usage: yes, in examples/graphics/Allegro/