Recently I posted a link to Mark McNeil’s entry about expecting more, and how as developers we need to get use to giving more.
Well, on that note, Zimbra is pretty cool. It’s a very nice groupware, outlook-like email/calendaring solution that is open source and has some amazing use of ajax
A couple of things I love about it is that you can hover over an address on any text and see a yahoo map of the location. You can highlight a date, or even relative date words such as "Today", or "Next Thursday", and the system will show a popup with the calendar for the appropriate day.
And did I mention it’s Open source?