Microsoft Train Simulator is one of the first train simulators on the market. It was released in July 2001 and developed by UK based Kuju Entertainment.
Many modifications to the "unplayable" locomotives have been made to make them player-drivable.
These original models were criticized by many people for being inaccurate. However, as with uktrain sim, people started creating and distributing their own models and other content through web sites. New routes, trains, sounds, cab views, and other MSTS accessories are available either as free ware or pay ware from various web sites and companies.
Included with Train Simulator was the Editors & Tools program, which mainly allowed the user to build railroads, or "routes", as they were called in MSTS. Users could also create activities for any route, create custom cab views, or edit the default ones.
The original version contained many bugs. For example, the "front coupling bug", where the locomotive's front coupler would not work, the "white void bug", where the route scenery disappears, leaving a white void, and the "end-of-the-line bug", where the locomotive, if it crashes through the last buffers on the route, would fall into an empty void.