Tom Hoffman and Tim Lauer are talking about using wikis, Rendezvous, and to create an in-classroom writing system for an elementary school. The teacher runs Instiki on a laptop. Students access it with Rendezvous Students write on the wiki and then the teacher can pack it up and take it home. This is a good example of a combination of simple tools.
Tim makes the point that there are many low-overhead Web applications that you can write to add value to the classroom, but they always run up against proprietary, closed student information systems (SIS). He developed SchoolTool as an open source SIS. SchoolTool has RESTful Web services-based APIs.
This allows the SIS and things like the wiki application to be integrated. A short hack to Instiki allows it, for example, to retrieve a student roster from SchoolTool.
SchoolBell is a calendar server built on SchoolTool. Its open-source as well and includes a GPL'd iCal server.