This article came up on the TextDrive Weblog last week and I just got around to reading it. I learned some stuff from it and it really makes you think about how exactly your code gets executed when you hit a URL and some of the things going on to make that happen.

Just a warning, it’s a pretty technical read and probably won’t make any sense to you if you don’t know what at least two of FastCGI, SCGI and Apache are.
VMUNIX Blues » FastCGI, SCGI, and Apache: Background and Future