Simplify the following text for a Grade 10 native English-speaking person.
Original: Tramlink ( originally and sometimes still called Croydon Tramlink ) is a tramway system in south London in the United Kingdom which began operation in May 2000 .
Simplified: Tramlink ( also called Croydon Tramlink ) is a tramway system in south London in the United Kingdom which began operation in May 2000 .