The Information Processing Technology Office (IPTO) of the Defense Advanced Research Projects Agency (DARPA) is soliciting proposals to develop an ontology-based (sub)system that captures, stores, and makes accessible the flow of one person's experience in and interactions with the world in order to support a broad spectrum of associates/assistants and other system capabilities. The objective of this "LifeLog" concept is to be able to trace the "threads" of an individual's life in terms of events, states, and relationships.