I saw your response below. I don't know anything about perl internals or embedding, but I know a little about threads. And I know generally perl is not "thread safe". If you're initializing something regarding perl in your main thread, then using it in the child threads, this is likely a bad idea. Also the sharing of anything among child threads or with the main thread should occur well outside the purvue of anything touching the embedded perl bits. If you keep things isolated in each thread, I don't see why you can't have isolated perl instances embedded there and using shared variables (outside of perl) to communicate (again outside of perl). But it'd get complicated quickly.