OpenCity

OpenCity is a free and open-source software 3D city-building game started in 2003 by France-based Vietnamese programmer Duong-Khang Nguyen. The game mechanics are similar to SimCity, although the game developers do not strive to make it a direct SimCity clone.

Gameplay
In the game, the player builds a city by marking land as commercial, industrial or residential zones. Those zones depend on each other to grow. The player is also required to supply the city with power and connect the different zones by building roads.

Origins and development
OpenCity is the product of programmer Duong-Khang Nguyen and 3D artist Frédéric Rodrigo. Nguyen was inspired by the open source game FreeReign; when he realized that the FreeReign project was cancelled and the source code was not in the condition to be improved, he began development on his own city-building simulator. The work in project started in 2003 with the registration on SourceForge. OpenCity is free and open-source software due to the licensing as GPLv2. Contributions to the game came from the game's community in form of translation and quality testing. OpenCity is built on cross platform libraries and APIs like Simple DirectMedia Library and OpenGL, which allows porting to various OSes and platforms, like Windows, OS X and many Linux distributions.

Reception
OpenCity achieved a broad spread as free and open-source and freeware video game, and was downloaded directly from SourceForge between 2003 and May 2017 over 190,000 times according to the SF download statistic. OpenCity has also been packaged for many Linux distributions: Fedora, Debian, SuSE, Slackware, Ubuntu, Pardus, Frugalware. OpenCity has been reviewed as "well made 3D remake" of SimCity by Chip.de in 2013.