What is this?
This map shows all trains (yellow dots) on the London Underground network in approximately real time. Geographic version, or Skyfall version.
I have similar things for the London buses, and an awesome bookmarkable train times journey planner. Donate
— Matthew
How does it work?
Live departure data is fetched from the TfL API, and then it does a bit of maths and magic. Some H&C and Circle stations are missing in the TfL feed.