*Régie Autonome des Transports Parisiens* or "RATP", a state-owned company responsible for most public transport in and around Paris, including the Métro, trams, buses and part of RER.

The RATP Group (French: Groupe RATP), also known as the Régie Autonome des Transports Parisiens (English: Autonomous Operator of Parisian Transports) is a state-owned public transport operator headquartered in Paris, France. Formed in 1948, the group has its origins as the public transport operator for the city of Paris. Its logo represents, in a stylized version, the Seine's meandering through the area around Paris as the face of a person looking up.

Today RATP is still responsible for most of the public transport in Paris and its surrounding Île-de-France region, including the Paris Métro, tram and bus services and part of the Réseau Express Régional (RER) network. In the Île-de-France region, RATP carries about 3 billion passengers per year.1

Whilst the RATP's Paris operations are still a major part of the business, its operations have now extended to include businesses around the globe. These include involvement in the operation of bus, tram, rapid transit and inter-city rail services, located in Europe, Asia, Africa and the Americas.

See here for the company homepage with the route planner.