Pugl is a minimal portable api for opengl guis which supports embedding and is suitable for use in plugins, but can also be used for programs.

pugl is vaguely similar to glut, but with some significant distinctions:
* minimal in scope, providing only what is necessary to draw
and receive keyboard and mouse input.
* no reliance on static data whatsoever, so the api can be
used in plugins or multiple independent parts of a program.
* single implementation, which is small, liberally licensed
and suitable for direct inclusion in programs if avoiding a
library dependency is desired.
* support for embedding in other windows, so pugl code can
draw to a widget inside a larger gui.
* more complete support for keyboard input, including
additional ??special?? keys, modifiers, and support for
detecting individual modifier key presses.