I'm trying OpenGL on Haskell and couldn't create the FreeGLUT DLL myself. I did follow this tutorial: http://netsuperbrain.com/blog/posts/freeglut-windows-hopengl-hglut/ But when I put my DLL on the folder of the binary, it complains about "initGlut". Using the DLL pointed by FreeGLUT official site, created by other person, works fine. I don't know what I did wrong. Anyone had this problem? Thanks.