FreeCol: a GPL reimplementation of Colonization with modern mechanics

An open source answer to a game whose original was abandoned

FreeCol is a turn-based strategy game based on the old game Colonization, and similar to Civilization, where the objective is to create an independent nation. The framing in the README is deliberately historical: you start with only a few colonists defying the stormy seas in their search for new land, and the question is whether you can guide them through the colonization of a New World. The project's stated aim is to create an open source version of Colonization, released under the GPL, and the team says that at first they tried to make an exact clone of the original. The visuals were to be brought up to date with more recent standards while remaining clean, simple and functional, and the gameplay and rules were to stay exactly the same as the original game. So the audience is two-sided: players who remember the original and want it running again, and people who want to work on a real codebase rather than a hobby mock-up.

The rules stay, the presentation and the multiplayer do not

The compatibility line is drawn precisely in the README. Certain new features are implemented, but the gameplay and the rules are exactly the same as the original, and the modern features named are an isometric map and multiplayer support. That is an unusual position for a remake to take: most projects that call themselves a clone drift towards their own ideas, and the ones that do not usually keep the original's 2D presentation. FreeCol does neither. The isometric view changes how the map reads without changing what a turn costs or what a unit can do. Anyone comparing this to a modern 4X title should notice that the design goal was fidelity first, so the feature set is not the point of comparison.

Incremental development, and a 1.0 that was never reached

The README describes a plan in two acts. First comes FreeCol 1.0.0, which is to be an almost exact Colonization clone, developed incrementally, meaning features are added one at a time so there is always a running program and an unfinished but working game can be released once in a while. Once 1.0.0 is finished, work would start towards FreeCol 2.0.0, which is to go beyond the original Colonization and become the implementation of the team and its users image of what Colonization 2 would have been. The release history shows how that played out. The tagged releases are v1.1.0 on 2023-05-20 and v1.2.0 on 2024-07-23, and the newest artefact is a Development Build dated 2026-10-19 rather than a version tag. The default branch is named sf-auto-merge, which points at an automated merge workflow rather than a stable release line, and the last push was on 2026-10-22. The project is alive, and it is also clearly living in the space between versions.

Weekly installers for Windows, Linux and Mac

Distribution is the most polished part of the project. The README states that the latest binary releases are created weekly and contain installers for Mac OS X, Windows and Linux, with the weekly releases linked from the GitHub releases page, and the badges at the top of the README point at both SourceForge and GitHub for downloads. For players this removes the usual friction of building a Java project from source. Note the distinction in the tags: the release list includes an entry called latest, labelled Development Build, alongside the numbered tags, so the weekly artefact and the stable tag are different things. The README also lists separate SourceForge trackers for bugs and for improvement requests, plus discussion forums, which tells you the project treats player feedback as part of its release process rather than an afterthought.

Building from source is one Ant command and Java 11

For developers, the build instructions are short. The README says to build the latest version of the code by running ant, and that this requires Java 11, Ant and the Java SDK:

ant

The ant task is the only command the README gives, and everything else about the build is left to the build.xml file in the repository. The repository layout backs that up, with a build.xml at the root and a build directory, alongside src for the Java sources, jars for dependencies, test, data, config and packaging directories, and schema and doc folders. There is also a freecol.iml module file, which is an IntelliJ IDEA project file, and a.travis.yml that points to an older continuous integration service. The doc directory holds developer.tex, which the README names as the place to read for more details on contributing to the project. In short: a conventional Ant-driven Java build with a document that tells you how the project expects patches to arrive.

The licence is GPL for code, and mixed for the content

The licensing needs two sentences rather than one. The source code is licensed under the GPL v2, and the repository metadata agrees. Most of the content, such as artwork, music and sound effects, is also under GPL v2, but some content is licensed under CC BY 4.0. The README instructs readers to refer to the README file in the same directory as the included content for more details, and the tree contains a srcdata directory and a data directory where those per-content files live. For a player this is invisible. For anyone who wants to reuse the art or the audio in another project, or to ship a derivative, the split matters, because Creative Commons attribution terms and GPL terms are not interchangeable and the mixture means the content cannot be treated as one uniform asset pack.

Editorial conclusion

FreeCol fits a player who wants the original Colonization ruleset in a maintained open source build, or a Java developer who wants to contribute to a long-running open source game with a working build and weekly installers. It does not fit someone who wants a modern grand strategy game with a large mod ecosystem, and the licensing of the artwork and audio is not uniform, so a commercial project needs to read the per-content README files. Before installing, take the weekly build rather than the last tagged release, and read the README next to the content you plan to reuse.

Frequently asked questions

Official sources

1. FreeCol/freecol on GitHub
2. Issues
3. License: GPL-2.0
4. README
5. Releases