Hi, I finally got bored of synchronizing accounts.xml with the other user and group databases, so I stitched together a simple NSS based user and group lookup directory service that simply uses the users and groups known to the system. You can set a prefix for groups and ranges for uids/gids to make sure system/admin users/groups don't end up having calendars. There's no location and resource handling yet although we could handle this too, but a proper LDAP interface might be more appropriate in that case. This directory service is not doing any authentication since everybody is doing Kerboeros anyways nowadays, so have fun! Pam would be possible to stich in too - but you'll have to hack up python-pam a bit which isn't worth it - so better get your KDC now! This was tested on Linux but should work on any unix based system. I'd be happy to adjust for other OSes if there are problems. The first patch adds the directory service itself while the second adds the defaults to twistedcaldav.config. Use: twistedcaldav.directory.nss.NssDirectoryService as DirectoryService and have a look at twistedcaldav.directory.nss for the available options. The patche are at Ticket #271 in trac: http://trac.macosforge.org/projects/calendarserver/ticket/271 Cheers, -- Guido