Excellent explanation of the concepts, well worth a ++.

You also have "low level" control of the pipes. You can create a pipe, fork() and use it to keep father and child (or siblings or whatever) happily talking to each other. The call to do this is (surprisingly) called pipe.

I would also recommend having people look at the IO::Pipe class that is a part of the core. It's very easy to use, and integrates nicely with IO::File, IO::Socket, et al.

--rjray