Author terms Allegro a game programming library, but it is very useful if you need graphics/sound/keyboard/joystick support in a program.

set of programs, C++ objects and C routines that allow users of Allegro's gui to make dialogs using better looking gui objects and extend the objects using more familiar normal C++ methods.

a free project to create VBE/AF(an extension of VESA) video cards drivers [sub project off-sprung by Allegro]