Web Document Authoring and Versioning. For an overview and many links, see http://www.webdav.org/. For details on versioning in WebDav see http://www.ietf.org/html.charters/deltav-charter.html.
See also:ChanningWalton (addedto by LisaDusseault)
Apple uses WebDav to support its .mac system for synchronizing multiple devices across an internet connection and for collaborative applications like the internet supported iCal software. --AndyPierce