Guide to Game Development/Rendering and Game Engines/OpenGL/GLUT

GLUT (pronounced like the glut in gluttony) is the OpenGL Utility Toolkit, a window system independent toolkit for writing OpenGL programs. It implements a simple windowing application programming interface (API) for OpenGL. GLUT makes it considerably easier to learn about and explore OpenGL programming. GLUT provides a portable API so you can write a single OpenGL program that works across all PC and workstation OS platforms.

GLUT is not open source. Mark Kilgard maintains the copyright. There are a number of newer and open source alternatives.

About
GLUT supports :
 * Multiple windows for OpenGL rendering
 * Callback driven event processing
 * Sophisticated input devices
 * An 'idle' routine and timers
 * A simple, cascading pop-up menu facility
 * Utility routines to generate various solid and wire frame objects
 * Support for bitmap and stroke fonts
 * Miscellaneous window management functions