Hi, I ran the Texture3D.hs redbook example from GLUT/examples/RedBook. After removing the initial check for error I got the following error from the program: Texture3D: user error (unknown OpenGL call glTexImage3DEXT, check for GL_EXT_texture3D or OpenGL 1.2) I've run the texture3D.c redbook example successfully and see the two colored rectangles displayed successfully. By the way I noticed that the .c code calls glTexImage3D, no EXT used. I'm running opengl 2.0. Mark