AnyEvent::Task is a pre-fork-on-demand server (AnyEvent::Task::Server) combined
with a persistent worker-pooled client (AnyEvent::Task::Client).

In a nutshell, a synchronous worker process is forked off by a server whenever
a client asks for one. The client keeps as many of these workers around as it
wants and delegates tasks to them asynchronously.

WWW: http://search.cpan.org/dist/AnyEvent-Task/