RFC2518 - This document specifies the Distributed Authoring Protocol, a set of headers and methods which extend the Hypertext Transfer Protocol to provide capabilities for overwrite prevention (locking), properties, and namespace management. - http://tools.ietf.org/html/rfc2518
IETF WEBDAV Working Group - Overview, mailing lists, draft documents, links to related working groups and to implementations. - http://www.ics.uci.edu/pub/ietf/webdav/
DAV Resources - Hosts Cadaver, DAVLib, Goliath, Mod_dav, Neon, and PerlDAV projects. Also includes news, a FAQ, links to other software and articles. - http://www.webdav.org/