North London Line
The North London Lind recently rebranded to the Mildmay line is a London Overground Line, which runs from Stratford (London) to Richmond and Clapham Junction. The North London Line used to go to North Woolwich until it was cut back to Stratford (London) to enable the DLR to take over the tracked between Stratford (London) and Canning Town as part of the planning for the Olympics.

Rolling Stock
Class 313
When London Overground took over the line from Sliverlink Metro, they inherited the Class 313 dating from the 1970s, these were replaced by the class 378 Capitalstars.
Class 387
The Class 378s were introduced as 3 car units known as the 378/0s in 2010, before being extended to 4 car and then 5 car units. The class 378s are currently undergoing a refurbishment.
Class 710
London Overground ordered 6 Class 710/3s to displace some 378s for an enhanced East London Line timetable as the 378s are the only trains permitted to run on the East London Line in passenger service.