thinking porting itslef is something that can't be done without testing, a module might help but cannot cover every aspect. Me too recommends Compaq's testdrive :) Porting threads, which are nearly impossible to implement afterwards when not designed in from start, as Dan Sugalski says, will be a none trivial thing. Since thread stabilty is very dependant on the platform, i'd stay away from doing stuff with them that got to be portable. I'd rather go with fork(). But me always does that, coming from UNIX, so i am sure i am biased ;)