Requiring Apache just to use WebDAV doesn't sound like the
right solution, and I'm not sure that investing 6 or 8 weeks to
write a module from scratch is ultimately the best approach
either.
I noticed that Jigsaw, the W3C's Java-based web server, has a
WebDAV module (http://www.w3.org/Jigsaw/). I wonder how hard
it would be to adapt it to work with nsjava.