SOcomGroupWare

Cosmo
What is Cosmo?

Cosmo 0.6 is the first release to include an experimentally usable web calendar application. Cosmo includes both a sharing server and web application pieces of the Chandler™ small workgroup collaboration suite. While the 0.6 release focuses on calendaring, Cosmo will eventually grow to support notes, tasks and lightweight communications.

Cosmo is a standards-based calendar server. Publish and subscribe to calendars on Cosmo with your favorite calendar application, including Chandler, Apple iCal, Mozilla Sunbird, or any application that supports WebDAV or CalDAV.

http://cosmo.osafoundation.org/