I've been trying to put the pieces together in my mind on what these products are. Kahuna is a beta version of hotmail (saying it that way probably does not do it justice). FireAnt is the underpinnings of Kahuna. It looks one of the big pieces of FireAnt is an Ajax-based user interface. If you have not read these, they are very interesting reads. My description is probably not 100% accurate, so please go read them as they provide a very interesting insight into product development and one of the drivers for Atlas.