Twiggy is a lightweight and fast HTTP server with unique features such as:

PSGI - Can run any PSGI applications. Fully supports *psgi.nonblocking* and *psgi.streaming* interfaces.
AnyEvent - This server uses AnyEvent and runs in a non-blocking event loop, so it's best to run event-driven web applications that runs I/O bound jobs or delayed responses such as long-poll, WebSocket or streaming content (server push). This software used to be called Plack::Server::AnyEvent but was renamed to Twiggy. See "NAMING" for details.
Fast header parser - Uses XS/C based HTTP header parser for the best performance. (optional)
Lightweight and Fast - The memory required to run twiggy is 6MB and it can serve more than 4500 req/s with a single process on Perl 5.10 with MacBook Pro 13" late 2009.
Superdaemon aware - Supports Server::Starter for hot deploy and graceful restarts.