GLUT 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. See http://www.opengl.org/resources/libraries/glut/.
GLUT is not open source. Mark Kilgard maintains the copyright.
The distribution consists of:
the source codes of the GLUT interface for BlackBox 1.5-1.6 (Windows only).
interface module to the DLL glut32.dll (isn't distributed with Windows, see Installation).
brief documentation and the Russian translation of Ogl documentation.
several auxiliary modules and example programs.