WebDAV with a Quota?

gik asks: "I'm in the need for a quota-managing, multi-account capable, class-1 WebDAV server (for remote file storage for clients). I've been researching WebDAV for a long long time now, and have only found one all-in-one implementation: Xythos webfile server, which is a very costly (but a very good) solution. I know that some online storage companies use a hacked Apache, but as anyone who's worked with WebDAV knows, doing this with Apache can be hard. So I'm asking: Does anyone out there know of a good WebDAV server with (hopefully) quota management that is as reliable and free as Apache? Oracle's IFS, Novell Netware, and the like are acceptable as possible candidates."