Anyone familiar with this? I'm looking into it because I may be setting up some collaboration. I asked a WebDav guru for some explanation of it which I've pasted below. I'm not sure if this is something I can do on PZ or not. One thing he says is "It's also possible you might be able to convince your local ISP to set up a WebDAV server."
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WebDAV is a network protocol, a standard way for two computers to communicate.
To use WebDAV collaboration features, you need client and server software that supports WebDAV. In your case, you have InCopy and InDesign, which both already support WebDAV as clients. So, you still need a WebDAV server. There are many WebDAV servers available -- Apache is one open source server that you could use, though it's tricky to set up. Sambar server
http://www.sambar.com/ is perhaps easier to set up, and is relatively inexpensive.
Yes, WebDAV works over the Internet. You need to create a space on the server which is password protected, then hand out username/password pairs to all collaborators. Then, you use InDesign and InCopy directly against that space you've created.
WebDAV builds on the HTTP protocol, so it doesn't use FTP.