01
OpenTTD
An open-source reimplementation of Transport Tycoon Deluxe with modern platform support.
An independent reconstruction of Fragile Allegiance
OpenTTD exists. OpenRA exists. So why is there still no OpenFA?*
Let’s change that.
Latest public preview 0.658.6 · Windows, Linux, Apple Silicon + Android APK · not a finished product · 7 October 2026
OpenFA is an independent reconstruction of the 1990s strategy game Fragile Allegiance. It recreates asteroid colony management, diplomacy and combat for modern systems, using behaviour documented in the original game.
Earlier open reconstructions
Inspired by projects that kept classics alive
OpenTTD and OpenRA are practical examples of long-running open strategy projects.
02
OpenRA
A portable engine for several classic Command & Conquer games.
03
OpenFA
OpenFA applies the same general idea to Fragile Allegiance, with separate code based on research into the original.
OpenFA is independent of both projects. OpenRA influenced some architectural decisions.
The original game
Mining was only the beginning
In Fragile Allegiance, you manage TetraCorp colonies in the Fragmented Sectors: survey asteroids, build settlements and ship ore to the Federation.
Prospect and colonise
Survey asteroids and establish working colonies.
Build an economy
Balance utilities, labour, storage and ore transport.
Deal with rivals
Trade and negotiate, or use espionage and sabotage.
Defend your claim
Research technology, build fleets and defend each colony.
Original game design
What makes Fragile Allegiance unusual
Fragile Allegiance combines colony management, moving asteroids, diplomacy, espionage, research and combat.
The original game remains commercially available from GOG.com and Steam.
The reconstruction
Rebuilding the game from original evidence
OpenFA reconstructs behaviour from the original program, game files, saved games and direct comparison with the game in action. Screenshots alone are not treated as proof.
OpenFA is
- An independent reconstruction of the original game
- A modern engine that runs on current systems
- Uses assets from a legally installed copy of the original game
- A base for preserving the original game and adding optional extensions
- A clear distinction between what is recovered and what is still uncertain
OpenFA is not
- A visual remake with invented rules
- A redistribution of the original game or its assets
- A fork of OpenTTD or OpenRA
- An official product
- A finished product
Content and extension packages
One format for content, mods and extensions
An .ofapkg can add or change parts of the game without rewriting the engine itself. This lets OpenFA keep a faithful version of the original game while also supporting optional extensions.
New contentBuildings, ships, missiles, ores, research, trade, personnel and scenarios.
Interface and visualsAnimations, HUD elements, extra on-screen information, status indicators and other presentation changes.
New rules and featuresPackages can use features provided by the engine and combine them into new gameplay elements.
The original stays separateThe standard game keeps Fragile Allegiance content and behaviour, while extra ideas can be enabled separately.
Packages already cover far more than the construction catalogue: new missiles, rare asteroid types, extra surface information, visual effects and industry systems are all possible. This is the format intended for OpenFA mods and optional extensions.
Reconstruction principles
How we keep OpenFA faithful to the original
- 01Check how the original behavesWe use the program, data files, saved games and recordings of the original in action.
- 02Do not fake the resultWhat appears on screen comes from the real game state, not a prepared animation.
- 03Compare the lookLayout, colours, layers and draw order are checked against the original.
- 04Do not hide guessesIf something is not known yet, it stays clearly marked as uncertain.
How the work gets done
How AI and automation are used
AI helps search the decompilation; tests replay known cases. Original data remains the reference.
01 / Analysis
Using AI to navigate decompiled code
AI helps find connections in the decompiled program and large amounts of game data. Important conclusions still have to be confirmed by the original game or repeatable tests.
02 / Verification
Automated regression tests
Automated tests check saved games, gameplay systems, graphics and repeatable situations taken from the original.
03 / Accountability
Manual review of names and visual fidelity
Names and fidelity claims are reviewed manually. Visual changes are compared in the target client.
Reconstruction in progress
Current reconstruction status
Current work is grouped as recovered, running or active.
Recovered
Original formats and palettes
Readers for picture, sprite, palette and video containers.
Recovered
Original saved games
OpenFA can read complete worlds from original saves: asteroids, factions, buildings, ships and other gameplay data.
Running in OpenFA
Asteroid surface reconstruction
Terrain, craters, buildable areas and graphic layers are reproduced from the original rules.
Running in OpenFA
Strategic map and original interface
The map keeps the original scale and look, shows sensors, owners and objects, and behaves normally under the mouse.
Running in OpenFA
Gameplay systems and tutorials
Construction, ship production, missiles, Asteroid Engines and the gameplay needed for tutorials 1–6 are already working.
Running in OpenFA
.ofapkg mods and extensions
.ofapkg packages can add content, new features and interface changes without altering the standard game.
Active work
Remaining original-game systems and multiplayer
We now understand how the original game kept multiplayer sessions synchronized. Playable multiplayer in OpenFA is still future work.
Reference comparisons
Original and OpenFA frames
Original on the left, OpenFA on the right. Select an image for full resolution.
Executable analysis
Original assets
Saved games
Watching the original game in action
Android preview
OpenFA on Android
Preview 0.658.6 includes a working Android APK alongside the desktop builds. Here is the asteroid colony running on an Android device.
Get the Android preview
Development journal
What we have learned so far
Entries cover verified milestones rather than individual changes.
Navigation, panels and Android
Preview 0.658.6 adds quick navigation, a minimap, detachable panels and a working Android APK.
Read entryA wider game view
Preview 0.597.22 expands the asteroid view beyond 640×480 while keeping the original interface sharp.
Read entryCommunity fixes and macOS
Reports from more preview players helped uncover missed bugs; 0.525.2 also adds an Apple Silicon build.
Read entry3D model studies
Buildings from a new perspective
These models grew out of Google rejecting OpenFA from the Play Store for “instability”. At the time, OpenFA depended entirely on Fragile Allegiance data and had no assets of its own, so the game could not start during pre-launch testing. With AI assistance, original-inspired 3D assets were created that could serve as an alternative graphics set in the future.
Full catalogue · 177 buildings
Seven cultures, search, culture filters, three views and rotation previews for selected assemblies. Downloadable Blend and GLB models.
Explore the full catalogue
Refined Terran · 40 buildings
Compare the earlier studies with more detailed models: hull plates, equipment, mechanisms and native PBR materials.
Compare the Terran modelsQuestions from the sector
Frequently asked questions
Can I play OpenFA today?
Yes, but only as a public preview. It is not a finished product and incomplete systems may fail. A local installation of the original Fragile Allegiance is required. Current builds are available from the openFA preview releases.
Will I need the original game?
Yes. OpenFA imports required data from a legal installation of Fragile Allegiance. It does not download or redistribute the original game assets.
Is OpenFA a remake or a source port?
It is an independent reconstruction. The original source code is not available.
What systems are available?
Public preview builds are available for Windows, Linux, macOS on Apple Silicon, and Android as an APK. These are development builds rather than supported final releases.
How closely will it match the original?
The goal is to match presentation and behaviour. Extensions stay in separate packages.
Will OpenFA support mods?
Yes. .ofapkg packages can add buildings, ships, missiles, scenarios, interface changes and new features supported by the engine. The standard Fragile Allegiance experience can remain untouched.
Is OpenFA developed with AI?
Yes. AI helps analyse decompiled code and correlate data. Findings still require original sources or reproducible tests.
Why does development progress in bursts?
It is a spare-time project, developed mainly in summer. There is no release schedule.
When will the source code be published?
No date yet. The source link will appear here when the repository opens.
Development journal
Read the reconstruction notes
The journal follows the major milestones, discoveries about the original game and new things that can already be seen or tested.
Enter the devlog