Collective Transport Company from Bucharest
Starting September 14th RATB became STB SA.
It operates a complex network of buses, trams and trolleybuses – in fact, all public transport except the Bucharest Metro, which is managed by Metrorex. While owned entirely by the City Council, RATB is an autonomous company.
The RATB transport services use a partially separate ticketing system to the Bucharest Metro (combined passes can be bought, but single tickets not). There are plans for the two transport systems to be merged at some point in the future.
History: http://www.ratb.ro/istoric.php