OpenCity is a free, open source 3D city simulator developed from scratch by France-based Vietnamese programmer Duong-Khang Nguyen and 3D artist Frédéric Rodrigo. Work started in 2003 after Nguyen discovered the open source city builder FreeReign had been abandoned and its codebase wasn’t worth salvaging. Rather than fork someone else’s unfinished work, he built his own from the ground up in standard C++ using OpenGL and SDL, with an original set of 3D building models and a SimCity-inspired zoning system. The result was downloaded over 190,000 times from SourceForge before development came to a stop with the 0.0.6.5 release in 2015.
OpenCity is the most honest entry in this list about what it is and what it isn’t. The official site says plainly that it’s not trying to clone SimCity and that development happens entirely in the developer’s spare time. What shipped is a functional 3D city-building sandbox with working RCI zoning, power, roads, and terrain editing, closer in scope to the early SimCity versions than to anything modern. Development is discontinued, but the game remains freely downloadable and is still packaged in current Linux distributions. It’s the most historically grounded 3D entry on our best free city building simulation games list, and for what it set out to do, it delivered.
Is OpenCity Free?
Yes, OpenCity is completely free and open source. The game is licensed under the GPLv2. There is no cost to download or play, no ads, and no paid edition of any kind. OpenCity has always been freeware and open source software from its first release in 2003 through to its final 0.0.6.5 build in 2015.
Gameplay & Features
The loop is classic zoning: mark land as residential, commercial, or industrial, connect zones with roads, and supply the city with power from an electric plant. The three zone types depend on each other to grow. Residential areas need jobs from commercial and industrial zones. Commercial zones need customers from residential areas. Industrial zones supply goods that feed the commercial and residential loops. Neglect one and the others stagnate. It’s a compact simulation that captures the essential tension of SimCity without the sprawl of its later sequels.
- Lightweight footprint. The installed binary is under 600 KB. Total installation with data is well under 50 MB. It runs comfortably on hardware from any era since the mid-2000s.
OpenCity is the sparest option in this collection, which is part of its value as a reference point. Players who want a richer economic simulation on top of the same core zoning model should look at LinCity-NG, which is actively maintained and goes considerably deeper. For the original SimCity source code itself, Micropolis is the place to start. The most polished free SimCity-like experience goes to TheoTown, while Cytopia offers the most visually ambitious open source take in a similar build-what-you-want spirit. The most different game in the set is The Final Earth 2 with its vertical colony format, and Unknown Horizons takes the genre’s economic logic in a completely different direction with its Anno-inspired archipelago setting.
PC System Requirements
OpenCity has no formally published system requirements. Given that the final release shipped in 2015 and was built on SDL 1.2 and OpenGL, it runs on essentially any hardware made in the last fifteen years. Windows and Linux are the most straightforward platforms. A macOS build exists for older releases but is not reliably available for current macOS versions.
| Component | Minimum | Recommended |
|---|---|---|
| OS | Windows XP+ / Linux | Windows 10 / Linux (current) |
| CPU | Any x86 or x64 | Any modern CPU |
| RAM | 256 MB | 512 MB |
| Graphics | OpenGL-capable GPU | Any dedicated or integrated GPU |
| Storage | 50 MB | 50 MB |
How to Download & Play OpenCity for Free
OpenCity is available from SourceForge and Linux package repositories. No account is required.
- Linux (easiest). OpenCity is packaged in Debian, Ubuntu, Fedora, and most major distributions. Search for
opencityin your package manager or software centre. The package is actively maintained in Debian’s repositories as of 2026. Install size is under 600 KB for the binary, with the data package adding around 40 MB. - Windows. Download the Windows installer for version 0.0.6.5 from the official OpenCity SourceForge page, an official, safe source. Run the installer and launch from the desktop shortcut. Download size is approximately 20 MB.
- Mac. No current macOS build is available. Older builds exist on SourceForge for legacy macOS versions, but these are not compatible with modern macOS. Mac users would need to build from source.
FAQ
Is OpenCity still being developed? No. Development stopped with the 0.0.6.5 release in 2015. The game is discontinued but remains fully downloadable and playable. Linux distribution maintainers continue to update the packaging, which is why it still appears in current Debian and Ubuntu repositories, but no new game features or content have been added since 2015.
Is it really a SimCity clone? The developer explicitly said it isn’t, and that holds up. The zoning and power model are drawn from the same tradition, but the implementation is original, the 3D engine is custom-built, and the scope is deliberately narrower than any SimCity release. Think of it as a city-builder that shares a genre ancestor rather than one that copies a specific game.
Why is the version number so low? OpenCity was always a solo spare-time project. Version 0.0.6.5 reflects honest versioning rather than feature incompleteness. The game is playable and stable at that version; the numbering just tracks actual development milestones rather than a marketing target.
