I may be missing something obvious here, but from the current FFI spec it appears that it is impossible to create libraries in haskell which are meant to be called from c code without running into undefined behavior. The problem is in the definition of hs_init() and hs_exit() . now, it is acceptable to have hs_init and hs_exit called in the initialization and finalization of your library, but the problem arrises when you link against more than one library which is implemented in haskell, suddenly whichever library is initialized secondly segfaults! (or whatever undefined behaviour means.). programs could suddenly stop working when a library is changed from a c implementation to a haskell one, which seems to be a bad thing. proposed fix: allow nested calls to hs_init, hs_exit, a counter is incremented when hs_init is called more than once, and decremented on hs_exit. only the last call to hs_exit will actually do whatever needs to be done. note that this cannot be implemented by the programmer himself since there might be several third party libraries also implemented in haskell which an app wishes to link against. this is sort of a showstopper for people (like me!) who wish to just use haskell as an implementation language for a library which is meant to be called from C. but then again, perhaps i am missing something obvious. John -- --------------------------------------------------------------------------- John Meacham - California Institute of Technology, Alum. - john@foo.net ---------------------------------------------------------------------------