A P2P Video-On-Demand Server.
You install one of these on a bunch of different machines. The different machines talk to each other. When a user requests a file from a server that does not have the file, it asks other servers for who has the file. Once it finds out, it then takes the file back from the server which does have the file, or if multiple peers have the file, it takes a chunk from each. As it gets the content from the other servers, it feeds it back to the user.
The code-base desperately needs refactoring.
P2P VodServer