The Privilege Separation patches for Apache HTTPD and 'mod_dav' address the problem that an Apache WebDAV server can only write files as the non-privileged Web server user (usually something like 'nobody' or 'www'). The patches address this shortcoming in a secure way by adding privilege separation to the Apache Web server (conceptually similar to SSH privilege separation). A privilege-separated Apache can be used to provide secure WebDAV write access to ~user directories and allow the use of per-user Unix quotas. When combined with mod_ssl, it provides a convenient and secure remote file serving system, as WebDAV clients are seamlessly integrated into both Windows and Mac OS X.
The Darwin Calendar Server is a standards-compliant server that allows multiple users to collaboratively share calendaring information. It provides a shared location on the network to store schedules, and allows users to send each other and manage invitations. In order to provide interoperability with multiple calendaring clients, the server implements the CalDAV protocol, which is an extension of WebDAV, which is in turn an extension of HTTP.