BVE Trainsim (originally Boso View Express) is a Japanese three-dimensional computer-based train simulator. It is notable for focusing on providing an accurate driving experience as viewed from inside the cab, rather than creating a network of other trains —other trains passed along the route are only displayed as stationary objects. BVE Trainsim was designed and developed by Takashi "Mackoy" Kojima starting in 1996 for windows 3.1/95. with the original program name coming from the Japanese 255 series multiple unit trains found in routes in Japan.
Although the internal working of the BVE Trainsim program itself cannot be modified, additional routes and train cab views can be added via a number of text-based configuration files. Route builders have produced over 300 additional routes for the program, along with matching cab environments. Routes built by independent developers simulate rail activity in Asia, North America, South America, and Europe.