Quality Open Source Calendaring / Scheduling?

Jim R. Wilson writes "In past jobs, I've used Microsoft Outlook/Exchange, Novell Groupwise, and Google Calendar for handling business appointments. I'm sorry to say it, but I have yet to see a rival to Microsoft's scheduling features. On Slashdot I have occasionally read rumblings that there are better open source email and calendaring solutions out there. Can anyone substantiate this claim? What are the OSS alternatives? Can any compete with Microsoft's resource scheduling?"

Comments

Citadel is *the* solution

[IGnatius T Foobar]

You really want to check out Citadel. It has a very comprehensive feature set -- not just calendars but also email, address books, message boards, instant messaging, access via all standard protocols plus a gorgeous ajax-style web user interface.

The best part about Citadel is that it is very easy to install. There's an automatic installer script right on the web site. No fuss, no muss, just enter the install command and watch it go. No tedious mucking about with integrating all of the pieces yourself, as the entire Citadel system is self-contained.

And the whole thing is GPL, unlike solutions such as Zimbra and Scalix which claim to be open source, but when you actually go there you find out that to get the full feature set you have to buy a commercial version. The Citadel project makes its very best work available to everyone on the same terms.