Open Train Times is a newly launched rail timetable and monitoring site, which will soon allow users to search for and track individual trains in real-time.
It uses "Open Data" provided by Network Rail and ATOC (which runs the National Rail Enquiries service), bundling it all up to let users track trains around the country. It's a little limited in scope at the moment, though, with only four rail networks currently supplying their data -- services operated by the London Overground, London Midland, Virgin Trains and National Express East Anglia are the ones currently included. Plus the exciting real-time running data part of the site is still "coming soon."
However, the seriously hardcore option to search by train identity (headcode) or the specific ID of the service is already in place, plus the developer says a more glamorous real-time visual map is in development.
Previous attempts at providing third-party open source train timetable data have met resistance, with National Rail Enquiries accused of restricting access to its live data streams and even going so far as blocking apps and sites that republish its minute-by-minute reports. So this is a big step in the right direction. [Open Train Times]