OpenTTD is an open source simulation game based upon the popular Microprose game "Transport Tycoon Deluxe", written by Chris Sawyer. It attempts to mimic the original game as closely as possible while extending it with new features.
Features(copy-pasta from wiki)
bigger maps (up to 64 times in size)
stable multiplayer mode for up to 255 players in 15 companies, or as spectators
dedicated server mode and an in-game console for administration
IPv6 and IPv4 support for all communication of the client and server
in game downloading of AIs, NewGRFs, scenarios and heightmaps
new pathfinding algorithms that makes vehicles go where you want them to
autorail/-road build tool, improved terraforming
cbrown towns, shiplifts, aqueducts
larger, non-uniform stations and the ability to join them together
mammoth and multi-headed trains
different configurable models for acceleration of vehicles
clone, autoreplace and autoupdate vehicles
the possibility to build on slopes and coasts
advanced/conditional orders, share and copy orders
longer and higher bridges including several new designs, plus fully flexible tracks/roads under bridges
reworked airport system with many more airports/heliports (e.g. international and metropolitan)
presignals, semaphores, path based signalling
support for TTDPatch NewGRF features offering many options for graphics and behaviour configuration/modification
drive-through road stops for articulated road vehicles and trams
multiple trees on one tile
bribe the town authority
many configuration settings to tune the game to your liking
save games using zlib compression for smaller sizes, while not interrupting gameplay
significant internationalisation support. OpenTTD has already been translated into over 50 languages
dynamically created town names in 18 languages, plus NewGRF support for additional languages
freely distributable graphics, sounds and music
framework for custom (user) written AIs
zooming further out in the normal view and zooming out in the small map
Servers
Server Name - Password - IP - Company Amount/Max
LilRobot's Stuph -
blockos - 174.52.180.12 - 1/15
Download here and join the fun!
http://www.openttd.org/en/Wiki for new players:
http://wiki.openttd.org/Main_Page
Gallery (share your pictures in thread):


Expand cities to be the largest in the world!

Compete with others to make more money and create the largest cities!