1. You have to tell ghc, that you want the HOpenGl Package when you compile some stuff that needs HOpenGL. You can do this with
in addition to the graphics (-package OpenGL), you also need some GUI, most likely GLUT (-package GLUT), if you're compiling red book examples. "ghc-pkg list" for ghc 6.4 should list "OpenGL-2.0, GLUT-2.0". as has been pointed out already, these differ substantially from the early tarballs. if you do "ghc-pkg describe GLUT", you'll see that the GLUT package depends on the OpenGL package, so it is sufficient to specify "-package GLUT" on the command line to get both. even easier is to use "ghc --make", as that will now infer the packages that provide the modules you import, so you don't need to specify either of GLUT/OpenGL explicitly on the command line. something like the following should work for the red book examples: ghc --make <example>.hs -o <example> you can find out what packages are installed and how to get access to them here: http://www.haskell.org/ghc/docs/latest/html/users_guide/packages.html and the documentation for the OpenGL and GLUT packages is here: http://www.haskell.org/ghc/docs/latest/html/libraries/index.html cheers, claus