StoryDB
StoryDB is a formalization of complex events with an accompanying persistence store. StoryDB is ideally suited for things like story development and investigative journalism. With StoryDB it is straightforward to (procedurally) create complex events and the precise relationships between events. StoryDB’s event model describes an event in terms of what is happening, when and where it is happening, who its participants are and why it is taking place.
StoryDB is an open source project maintained at GitHub.