Zeitgeist is an “event logger”. It registers the activity of the user on the desktop, what documents uses, when, while talking with who, combined with what… and then different UIs can consume this data to show a Journal of activity, a better relevance in the searches, related documents to the one you are working on and [write your own cool idea here].
Tracker and Zeitgeist are complementary projects: Tracker knows the documents, Zeitgeist knows the activities. We (tracker developers) have been talking with Zeitgeist developers before and have a common understanding about the big picture. Now is time to start fixing details, and I’ll be next week in the Zeitgeist hackfest to work on that.
By the way, with some patience and fixing few details, Zeitgeist and Tracker 0.7 can be installed in maemo5. Catching few events here and there, zeitgeist can grab some basic informacion, and somebody could write a Journal home-screen applet, like the call log, but about all kind of activities/documents… Quite an interesting project.