Try to find OpenGL
Once done this will define
OPENGL_FOUND - system has OpenGL
OPENGL_XMESA_FOUND - system has XMESA
OPENGL_GLU_FOUND - system has GLU
OPENGL_INCLUDE_DIR - the GL include directory
OPENGL_LIBRARIES - Link these to use OpenGL and GLU
If you want to use just GL you can use these values
OPENGL_gl_LIBRARY - Path to OpenGL Library
OPENGL_glu_LIBRARY - Path to GLU Library
On OSX default to using the framework version of opengl People will have to change the cache values of OPENGL_glu_LIBRARY and OPENGL_gl_LIBRARY to use OpenGL with X11 on OSX