Q. I mounted my web server via WebDAV but it's read-only.

A. Go to ServerAdmin, Web, Configure Web Service, Sites tab, and check the Name of your web server. It needs to match your DNS name exactly. So if your web server is "gateway.example.com", the Name needs to be "gateway.example.com". if it's just "gateway", everything will work properly except that WebDAV will mount the volume read-only.

A. Also check your permissions on your /Library/WebServer/Documents/ folder and make sure it's writeable by either the user www or the group www.

In case you thought this meant stuff like XML-RPC and SOAP, OS X has them both built in. See Apple's site on AppleScript Web Services