Twitter is using BitTorrent internally for faster deployment
This is what they revealed in a video floating around lately. Instead of sending thousands of git pull requests to each of their deployment servers , Twitter started using the BitTorrent protocol from Python to distribute the binaries in their deployment cycle. They report a drastic speed improvement.
They call this "Murder", and the code is freely available at http://github.com/lg/murder.
Here's Larry Gadea describing Murder: