I have been working on a Haskell interface to the platform API for Haiku (was BeOS.) It's C++, but the interesting thing at the moment is the use of threads - a UI window gets its own thread, and whatever Haskell code will be executed by callbacks from that thread. So it was surprising when this turned out to be incompatible with the -threaded link option. With that option, I get one callback from a non-main thread, and then that native thread will die, shortly after return from the callback. Results without -threaded are not really so good either (the application may run and work for a while, but inevitably fail with various errors that I suppose might be expected), so ... what do my threads need, to make -threaded work? The callbacks are `foreign "wrapper"' functions, which means rts_lock() is already getting called. It looks to me like that should work the same as if my thread had been invoked via forkOS, true? Is there anything else that I missed, that needs to be done to set the thread up for GHC? (I had been thinking this would not be a unique situation, rather there would be several other GUI toolkits out there that use threads in this obvious way, but after a brief review of the ones I usually hear about, not so sure. If there's another library that uses OS threads this way, with Haskell bindings already, that might be something I could steal a clue from.) thanks! Donn Cave, donn@avvanta.com