Krasimir, Daan, I get: /home/as49/local/bin/ghc Graphics/UI/HGUI/OS/Window.hs -O -c -fglasgow-exts -Iincludes -I/usr/local/include -I/usr/local/include/glib-2.0 -I/usr/local/lib/glib-2.0/include -I/usr/local/include/atk-1.0 -I/usr/X11R6/include/pango-1.0 -I/usr/X11R6/include/gtk-2.0 -I/usr/X11R6/lib/gtk-2.0/include -I/usr/X11R6/include -I/usr/local/include/freetype2 -I/usr/local/include -package-name HToolkit Window.hsc:24: failed to load interface for `Graphics.Data.Geometry': Could not find interface file for `Graphics.Data.Geometry' Window.hsc:25: failed to load interface for `Graphics.Rendering.HGL.BasicTypes': Could not find interface file for `Graphics.Rendering.HGL.BasicTypes' Window.hsc:26: failed to load interface for `Graphics.UI.HGUI.BasicTypes': Could not find interface file for `Graphics.UI.HGUI.BasicTypes' Window.hsc:27: failed to load interface for `Graphics.UI.HGUI.OS.Types': Could not find interface file for `Graphics.UI.HGUI.OS.Types' Window.hsc:28: failed to load interface for `Graphics.UI.HGUI.OS.Util': Could not find interface file for `Graphics.UI.HGUI.OS.Util' gmake: *** [Graphics/UI/HGUI/OS/Window.o] Error 1 There is no directory OS in HGUI. I configured with ./configure --with-hc=/home/as49/local/bin/ghc --enable-gui Axel.