Hi John Fair points - but aren't you always going to 'need' at least MinGW? (for some degree of 'need' of course, I use it quite a bit though prefer Cygwin, I suppose Andrew C. would care not to use either). GHC brings with it gcc and ld, ar ... but not much else, so when a C library isn't all but self-contained, you would have to use MinGW to get the .a file - SDL for instance just distributes the .dll in the runtime library package. Also gnuwin32 is a wee bit spartan by my consideration [1], but perhaps you could knock my 95% guess for Hackage bindings libraries needing Unix emulation down to 60%, or 50%. Likely I was wrong with my guestimate in the first place by thinking mainly about 'multimedia' libraries. Best wishes Stephen [1] Presumably you mean here? http://gnuwin32.sourceforge.net/ http://gnuwin32.sourceforge.net/packages.html