FastCGI Development Kit.

FastCGI is a fast, open, and secure Web server interface that solves the
performance problems inherent in CGI, without introducing the overhead and
complexity of proprietary APIs (Application Programming Interfaces).

FastCGI allows for many nice features such as persistent CGI applications
(eliminating process creation time per request) and being able run CGI
applications on hosts remote to the web server itself.

Most web servers have optional or add-on support for FastCGI. Applications
which are developed with FastCGI behave as standard CGIs when invoked by web
servers without FastCGI support. In other words, if the server supports
FastCGI, then FastCGI applications get all the perks (mainly being *really*
fast); if the server does not support FastCGI, then FastCGI applications
behave exactly like standard CGIs.