As a demo for the first day of class, I thought I'd try to write a simple shell in Haskell, in part so I can show algebraic data types and monads on the first day, but also to convince potential skeptics that functional languages can do systemsy things. All the usual functional stuff is going very nicely, but I don't seem to be able to get my hands on pipe(2) at all, and the language in the documentation for fork() and exec() might as well read Here Be Dragons. Looking for ways to fork, it appears that I have a wealth of abstractions to choose from: System.Process System.Posix.Process IO The 'new' System.Process on the web appears to have some very nice facilities, although it is still not strong enough to do what I want cleanly (capture the output from a command that might be internal or might require me to fork an external process). However, the question is moot because my system seems to have a consistent set of libraries coordinate with the release of GHC 6.8, and I don't know how to put together a consistent set of 'new' libraries to go with 6.10. (I don't even know if such a set exists.) Please advise me: should I give up the idea of writing a shell using GHC and the classic Unix system calls fork/exec/close/pipe? Or if it is possible after all, in what module should I be looking for the proper abstractions? Norman