Simutrans

Simutrans is a cross-platform, open source transportation simulation like Transport Tycoon Deluxe. The main goal is to run a transportation enterprise via constructing and managing transportation systems for passengers and goods. This could be done via rail, road, trolleybus, tram, monorail, metro, suspension railway, ship and airplane.

You can play with up to 15 enemy companies, controlled via AI or other human players in LAN or Internet.