What is "freeglut"

FreeGLUT is an open source alternative to the OpenGL Utility Toolkit (GLUT) library. GLUT (and hence FreeGLUT) allows the user to create and manage windows containing OpenGL contexts on a wide range of platforms and also read the mouse, keyboard and joystick functions. FreeGLUT is intended to be a full replacement for GLUT, and has only a few differences.

Since GLUT has gone into stagnation, FreeGLUT is in development to improve the toolkit. It is released under the MIT License.