Coro is a package providing both low-level coroutines as well as a high-level multitasking abstraction on top of Perl. It allows you to parallelize LWP and other network protocols with ease. Unlike the so-called "Perl threads/fork emulation", they provide a real shared address space (like real threads) without the associated race conditions and performance loss, while maintaining a very low memory overhead (2-3kb/coroutine). The package comes with examples and many supporting modules.