Howtoforge posted a guide about setting up WebDAV with MySQL authentication on Apache2 under Debian 4.0

This guide explains how to set up WebDAV with MySQL authentication (using mod_auth_mysql) on Apache2 on a Debian Etch server. WebDAV stands for Web-based Distributed Authoring and Versioning and is a set of extensions to the HTTP protocol that allow users to directly edit files on the Apache server so that they do not need to be downloaded/uploaded via FTP. Of course, WebDAV can also be used to upload and download files.

How To Set Up WebDAV With MySQL Authentication On Apache2 (Debian Etch)