Check out the IndieLib FAQ on the Wiki.

What is Indielib?

ndieLib is 2d game engine in C++ for game development with tutorials, api reference, entity system, sprite animations, collision detection, 3d hardware acceleration, bitmap and TTF fonts, 2d parallax scroll, 3d objects, 2d cameras, viewports, timers, alpha blending, shaders and image filters. Check the full list of features in the Indielib FAQ.