Christian Weiske has a recent post to his site looking at something most PHP developers don't even think about when serving up their scripts - the MIME types for PHP files.

While setting some svn properties at work, we wondered about the correct MIME type for .php files.

He found several in the official IANA list including "text/php", "application/php" and "application/x-http-php" - all valid but none of them considered a standard. He talks about the ones supported by linux distributions (like Debian/Ubuntu) and some reasoning that might make "application/php" the best choice of the list. He points out some downsides to the choice, though, including the fact that something starting with "application/" should considered "machine readable" only despite PHP just being text.