Set up WebDAV on OSX in 5 minutes
shawnwall.com: teach("webDAV + iCal")
Shawn says Mac OS X 10.2 is required, but I have just confirmed that his instructions work on 10.1.5 as well. So if you want to have a 10.1.5 machine acting as a WebDAV server for your Jaguar clients, you can!
If you're copy/pasting his commands, watch out for his misspelling of the "Webserver" directory which should be "WebServer".