Hi, I decided to try compiling Hat on Windows, just the viewing tools, using only the standard Windows tools and those things which get installed by GHC for Windows. It worked with a few tweaks/changes, so I thought I'd document them here: cd ...\hattools gcc -c *.c -DFILEVERSION="\"2.04\"" -DVERSION="\"2.04\"" (hat-anim.c fails totally) ghc --make HatCover.hs -cpp -fglasgow-exts artutils.o finitemap.o pathutils.o ghc --make BlackHat.hs -cpp -fglasgow-exts artutils.o finitemap.o pathutils.o nontermutils.o gcc hat-check.c In addition I also commented out the 4th line in finitemap.h, #include "checkglib.h". Creating an empty checkglib.h would have solved this one. I also commented out the signal lines in hat-check. I also copied art.h into the tools directory, although an -I flag would have worked here instead. I also defined ntohl myself, since its not defined in any of the default C libraries on Windows. unsigned long ntohl(unsigned long netlong) { return netlong; } With these changes I could get compiled versions of most of the tools. Thanks Neil