The Thread module is deprecated.

If you want to use threads for anything serious, get a new version of perl (at least 5.8.0, but the latest version, 5.8.8 is probably best) compiled with threads enabled. update: and then get the latest versions of threads and threads::shared from CPAN.

See also threads and threads::shared.

As for IPC, threads (not really IPC, but similar), sockets, shared memory and signals are some of the more popular options. Which one is the best/easiest depends on what you're trying to achieve.

updated again: fixed link to threads::shared