source code -- open source, free software
see also: play.org Lisp links
This is optimized for high performance web services with a security mindset: minimizes network traffic, reduces client & server processing, prevents end users from spoofing headers (eliminates any possibility of duplicate hash key attacks within the CGI app) and potentially helps avoid dynamic memory allocation on the other side of the socket.
[UPDATE: This project has been abandoned in favor of using
Nginx's proxy_pass
directive.]