Plack is a set of PSGI reference server implementations and helper utilities for Web application frameworks, exactly like Ruby's Rack. It supports Standalone, CGI, FCGI, Apache, AnyEvent, Coro, Danga::Socket and many other server environments.
I'll be talking about PSGI and Plack at SF.pm meetup. Will start with the general introduction but will include lots of updates since YAPC::Asia and Six Apart engineering tech talk. I'll also mention a little about my event-driven web framework Tatsumaki.
Come to the meetup if you're in the bay area.