Open Source Groupware/Calendaring?

Sysadmin John Goerzen posted a list of events he was thinking of attending. I sent him mail explaining that we were trying to expand the sysadmin content at OSCON and asked him what he’d like to see. One item caught my eye: Groupware/calendaring solutions. This has been a big hurting point in free software for a while.”

I immediately thought of Hula from Novell, which was going to attack this very space. However, Hula has rather abruptly been discontinued (the “project”‘s homepage is an FAQ for the sale of a Novell product to another company). Mozilla have Sunbird, but it’s still early days. Chandler isn’t a contender. O’Reilly is using Zimbra for email but not for wider scheduling., and the conferences group throws a lot of Google Docs around in lieu of file-sharing Word files. There are piles of Zope and PHP tools, but what’s actually used for calendaring and groupware in the real world? Leave a comment and tell me what your company uses ….