What is FastCGI? I could go on for pages about the technical background, and Microsoft already has some great documentation on the subject, however I'll put it in layman's terms for those who aren't Computer Science majors. [...] CGI is a method that a web server can use for tools like PHP, Perl, or any other language that support it. CGI spawns a new process for each request, which can be really slow. FastCGI speeds this up with a very simple solution '" instead of creating a brand new process for each request, it creates a "pool" of processes and reuses them.
She talks about her usage of PHP on Windows platforms in her work, about a move her company made from Apache to IIS and how much the FastCGI functionality helped. She also briefly explains how to get IIS and FastCGI to work together to make the PHP functionality happen.