A train simulator (also railroad simulator or railway simulator) is a computer based simulation of rail transport operations. They are generally large complicated software packages modeling a 3D virtual reality world, with ‘play mode’ software which lets the user interact by stepping inside the virtual world. Some, like the first Microsoft Train Simulator are written and modeled for the user mainly interested in driving.
Like flight simulators, train simulators have been produced for railway training purposes. Driver simulators include those produced by:
Ongakukan in Japan
EADS in Germany
Bentley Systems in the UK
Lander Simulation & Training Solutions, Spain 
Transurb Technirail, a Belgian company based in Brussels
CORYS T.E.S.S., a French company based in Grenoble
Krauss-Maffei Wegmann GmbH & Co KG (KMW) www.kmweg.de/, a German company based in Munich
Sydac a member of the Knorr-Bremse Group based in Australia.
OKTAL, a French company member of the international group SOGECLAIR based in Toulouse
New York Air Brake, an American company based in Watertown, NY.
PS Technology, an American company based in Boulder, CO.
Signaller training simulators have been developed by Funkwerk in Germany, The Railway Engineering Company (TRE) in the UK, OpenTrack Railway Technology in Switzerland, and PS Technology in the US