We just set up Zimbra at work, and I'm really pleased with it. But I'm a little wary of the fact that Yahoo! just bought Zimbra. What will happen to this platform next? Nothing bad, I hope...
Here's why I like Zimbra, as opposed to the other open source groupware server packages out there. (Where to start?)
1) Zimbra is made up of familiar pieces. It uses the Unix philosophy, which is to write relatively small applications and then glue them together to do big jobs. In that vein, Zimbra uses Postfix, Apache, and other tried and true tools at its base.
2) Zimbra can be used with all your usual clients. It works with IMAP or POP3, and even has an available (non-open) Exchange-like piece that you can use for your (shudder) Outlook users. It also has nice, standards based things like an ical version of your calendar, which you can use to connect up with standards-friendly calendar clients.
3) Zimbra has a fantastic Web-based client. It's all AJAXy and buzzword compliant, but that's not what's great about it. My favorite part about it is actually reason #4...
4) Zimlets. Zimlets let you create all sorts of extensions that will work in Zimbra. Here at this company we're in the process of planning the next generation of their whole in-house software system, and I'm putting Zimlets at the core of several pieces of that software architecture. Customer service, billing, accounts payable, marketing, and supply-chain will all have direct access between their respective job-function-related applications and Zimbra, both ways. For instance, a CS rep will be able to read an email sent to service@..., mouseover the customer name to see that customer's key info or mouseover the order number and get info about that particular order. Click on either one and the cs rep will go straight to the full editable customer or order page. All this, of course, will be based on Zimbra group permissions which will be sync'd up with the user/group permissions on the Web interface for our customer service tools.
As you can see, I'm very excited about the possibilities. This is why I keep working in this industry. Fun stuff. :)