This looks like the sort of tool I’ve been looking for – a content management system with the appropriate granularity for teaching, such that text, images and other multimedia elements are stored in a database, and there is a presentation / editing tool to allow use of elements in the database in a given teaching situation.
It’s been developed at Princeton, there is a Building Blocks integration to Blackboard, and it is Open Source – sounds ideal, although I’ve not examined any of the details yet, and the devil is always in the detail …