OpenCity

OpenCity is a 3D city building game started in 2003 by Duong-Khang Nguyen, licensed under the GPL. . It's coded in C++, uses the OpenGL and SDL libraries and the OGRE rendering engine. While it's similar to SimCity, it is not intended to be a direct clone.

The last stable release, 0.0.6.5, was released on March 15th, 2015.

Gameplay
The player starts off with 15000 acons (OpenCity's own fictional unit of currency) on a randomly generated map. They have to build a city by marking land as commercial, industrial or residential zones. These zones depend on power supply, being connected to roads, and on each other to have buildings develop. Other buildings, such as police stations and hospitals, are also available to be built directly to improve the lives of your citizes.

The game doesn't have a budget screen or any statistic screens, making it difficult to figure out how well your city is doing without trial and error.

Manual
The OpenCity website offers a 'Manual' on how to play the game, split into these five webpages:
 * Getting started guide
 * Tutorial - Toolcircle
 * Tutorial - Powering
 * Tutorial - Status bar
 * Tutorial - Main menu

Development
OpenCity was created by Duong-Khang Nguyen and Frédéric Rodrigo. Browsing the internet for games, Nguyen discovered an open source city building game called Free Reign, which was sadly left abandoned. After looking at its source code, he realized it was too confusing and didn't fit his programming style. This led to him creating his own FOSS city building game, OpenCity. It was registered on SourceForge in April 2003. Many others have also contributed to the project, from 3D artists to translators and testers.

There are three branches: Stable, Beta and Development. The OpenCity project has a TODO list detailing what needs to be done before releasing a new major version. The development team was also taking suggestions from the player base. One of the icons on the query tool is a water icon, which suggests that water management was planned to be implemented into the game.

Development team and contributors
A credits page is available on the OpenCity website, which lists the following:

Code: Art: Testing: Miscellaneous:
 * Duong-Khang Nguyen - Project lead
 * Stephen M. Webb - Configuration patch
 * Victor Stinner - Multi-agent system
 * Frédéric Rodrigo - Lead 3D artist and ideas brainstormer for the game
 * Nicolas Pascoli - Various 3D models
 * "pucelo" - Various industrial 3D models
 * Bruno Dlubak - MacOS X beta tester
 * Tymon Douglas - Linux and Windows beta tester
 * Wolfgang Bauer - Linux beta tester
 * Bartosz Debski - OpenCity's homesite banner
 * Cristian Deluxe - Spanish documentation
 * Jacopo Sirianni - Italian documentation

Reception
OpenCity has been downloaded over 190,000 times through SourceForge. OpenCity was integrated in various Linux distributions, such as Ubuntu, Debian, Fedora and OpenSuse. But it was removed from some of them, such as Arch Linux and Slackware, possibly due to the lack of updates.

A german tech website, Chip.de, wrote a page about the game in March 2013, calling it a "lovingly made 3D remake of the classic game SimCity", but also stating that the game "only has a fraction of the features originally planned".

Version history
Some of the changes between each major versions are showcased on the OpenCity screenshot page.