From LQWiki
Simutrans is a transportation and economic simulation game. Somewhat simliar to Transport Tycoon Deluxe and OpenTTD. Its license is free-as-in-beer. The normal version uses 64x64 pixel tiles, but there's also an more detailed 128x128 graphic set available. There are also several addons available (like more vehicles, extra industry chains,etc). It uses SDL.
This page is available under a