This code is a modified version of Sylvain Schmitz's PHP RSS feed. His code and my changes are both released under the GFDL.
I wanted an RSS feed of my watchlist almost immediately after joining Wikipedia. Unfortunately, the Wikipedia software doesn't support that feature. It seems that many wikipedians have been hacking away at the problem, but none of the solutions on that page worked for me. Sylvain Schmitz's was close, but I didn't want to have to post it to a (public) webserver (and I don't speak french). So, I started hacking away at Sylvain's code to see if I could make it do what I want. This is the result; may you find it useful.