GLFW is a free, Open Source, multi-platform library for creating OpenGL contexts and managing input, including keyboard, mouse, joystick and time. It is intended to be simple to integrate into existing applications and does not lay claim to the main loop.
GLFW has native support for Windows, Mac OS X and many Unix-like systems using the X Window System, such as Linux and FreeBSD.
GLFW is licensed under the zlib/libpng license.
Web Site: http://www.glfw.org/