OpenTTD

OpenTTD ("Open Transport Tycoon Deluxe") is a freeware, open-source remake of the traffic simulator from 1995. It greatly expands the original game, featuring lots of new additions and maps several times larger in size. The default game distributions include entirely new graphics and sound resource files, but the player can use the assets from the original game or download entirely different custom sets made by other fans.

The main objective remains the same, to create and maintain a complex infrastructure of transport units and connect the industry installations of a region. The map is randomly generated at the start, where several initial parameters can be tweaked to produce unique environments. Custom maps and scenarios can also be built with the integrated editor.

Compared to the original Transport Tycoon Deluxe, OpenTTD supports more elaborate stations and signals, longer and more varied bridges, more objects on the map and more vehicles/stations per player, canals and locks, tunnel crossings, order copying, and more. The multiplayer mode has been expanded to support 15 companies between up to 255 players, and a dedicated server system. Many of the game's aspects (graphics, objects, audio, AI) are modular and can be edited by the community, then distributed through the in-built mod repository.