Open BVE is based on Boso View Express or BVE Trainsim as it is called these days.

You can find the original program on this website http://mackoy.cool.ne.jp/ and there are tonnes of trains and routes available, most of the are bare-bone routes but some rival commercial produced titles.

And i have been playing with it for years.

Robert van der Veeke Basugasubasubasu Basugasubakuhaku Gasubakuhakuhaku!! "Better is the enemy of good enough." Dr. Mikoyan of the Mikoyan Gurevich Design Bureau.