Trains are awesome. Everybody loves trains.
With OpenTTD, one can enjoy train business simulation using a personal computer, with no need of actually getting into train business!
That’s another libre clone1 of an older game, with some additional development on top of that. One of the cutting-edge technologies that OpenTTD applies is an additional sensory output: not just you see and hear trains, but you can also smell the burning dirt – supposedly from a video card. Not like there are any fancy graphics, so it can’t be a mere side effect.
Apart from trains, it includes some busses, ships, and aircraft. You build roads, airports, and other stuff, collect money, build more – in a loop. With no way of enjoying what you’ve earned, or any meaningful goal: that’s how good it is at simulating a train entrepreneur’s life.
More of FOSS clones can be found on osgameclones.com. And libregamewiki.org lists some of those, as well as original games.↩