Hula - Open Source Groupware for the Corporate Soul.
There’s lots more out there on all aspects of this than I care to even think about, but some of the things that Nat has written about it in his weblog sound pretty cool. Personally, I have only one wish for this product: for it to become something that I can use in the workplace for task/appointment management. Currently, we’re in a 20% Windows/80% Mac world, but all the appointment management is done through Outlook and ACT!. The number of times I’ve heard the people who use it cursing ACT! is way too high, and it has the obvious problem that the rest of the office can’t use it.