WenDav Server .Net

i founnd a site http://www.ithit.com/ for WebDav .Net
here he implimented server using HttpListener class and No IIS is required to run this server.So we can't write an ASP.net DAV server.
Write an ISAPI filter, very similar to the "AuthFilt" sample that comes
with the IIS resource kit. This (I believe) will allow me to authenticate
against any and all requests that come into the IIS server, including the
WebDAV requests that I need.