openOMSI (OMSI 2 rewritten in Rust)

OMSI 2 (MR-Software, published by Aerosoft, 2013) is a Windows bus simulator with a huge modding scene. It is a 32-bit program, so big maps hit its 2 GB memory limit. openOMSI rebuilds the engine around that content. The repository was created on 27 September 2026. It had about 670 stars, 190 forks and over 700 open issues when we checked on 22 October.

What it is

• A new engine, not a patch: written in Rust, 64-bit and multithreaded, rendering through wgpu (Metal, Vulkan or DirectX 12, with OpenGL fallbacks). It has four graphics modes, from Vanilla (looks like OMSI 2) to Enhanced+ with ray-traced shadows and reflections.
• Your content, unchanged: the README says maps, buses, AI traffic, scenery, scripts, timetables, HOF files, weather and plugins load the way OMSI 2.2.032 loads them. The OMSI 2 folder is never written to; mods go in a folder of their own.
• No original code or assets: the project’s goals say nothing is copied from the original. Instead the file formats are documented in the repository.
• Extras: a launcher (map, line, bus and livery on one screen, mods from a folder or archive, wheels and pedals with force feedback), LAN multiplayer and a dedicated server, VR through OpenXR on Windows, and Lua or WebAssembly plugins.

It belongs with other engine rewrites like OpenTTD (see OpenTTD in the browser). Like them, it doesn’t emulate or decompile the original program; it reads the original game’s data with new code.

The README doesn’t say whether AI tools were used. Wikipedia’s OMSI 2 article says they were, and some contributors’ branch names point to AI coding tools, but we couldn’t confirm it from the project itself.

Current status

The launcher updates itself, on a Stable or Beta channel. Builds are unsigned, so Windows SmartScreen and macOS Gatekeeper warn on first start; the README explains how to open them anyway.

What you need

• OMSI 2 installed with its stock content: the Steam Edition or the retail version. openOMSI targets OMSI 2.2.032, the current version. The launcher usually finds it; otherwise point it at the folder with Omsi.exe, maps and Vehicles.
• On Mac and Linux: OMSI 2 itself is Windows-only, so the files come from a Windows install. Linux needs a Vulkan or OpenGL driver and WebKitGTK 4.1 for the launcher.
• On Android: the OMSI 2 folder is copied onto the device first (see the project’s Android guide).
• Any add-on maps and buses you want to drive, installed as you would for OMSI 2 or through the launcher’s Mods page.

We don’t explain how to obtain or copy game files.

Community projects

These are independent projects, not official openOMSI releases. We link only their repositories.

• openOMSI-ios (Ziran123lst, unofficial): an iPhone and iPad port that patches the upstream code and renders with Metal. It builds an unsigned .ipa that you install through LiveContainer (with SideStore or AltStore), then import your OMSI 2 folder through the Files app. The README says it follows upstream releases automatically, but its newest build when we checked was from 7 October 2026, behind the official version.
• openOMSI Editor (DarkBat2709, unofficial): a fork of openOMSI with an in-game map editor for roads and splines, roundabouts, AI traffic paths, terrain and scenery. Version 0.8.8.1 (20 October 2026) is based on openOMSI 0.3.33, for Windows x64 and Linux x64, with English and German guides. It still needs OMSI 2 content. The official openOMSI has only an object editor for existing scenery.
• openOMSI map packages (lmonteirotech, unofficial): extra layers for openOMSI’s navigator and city map (water, parks, streets, contour lines, lines and timetables) for Berlin-Spandau, Projekt Szczecin and Fikcyjny Szczecin, plus the generator to make your own. The packages contain OpenStreetMap data and line data worked out from each map’s timetable. They don’t include any of the maps’ files, so you still need the maps themselves.

A separate Rust recreation of OMSI 2, neoOMSI, was started by developers who left openOMSI. It is a different project.

Is it legal and safe?

• openOMSI is an unofficial fan project, not affiliated with Aerosoft or MR-Software. It ships no OMSI 2 content: you need your own copy of the game.
• The official sources are the openOMSI-org GitHub repository and openomsi.org. The project’s trademark notice warns that look-alike names are not official. The old GitHub Pages addresses (turbo-devv.github.io/openOMSI and openomsi-org.github.io/openOMSI) were earlier homes of the same site; the second now redirects to openomsi.org.
• Each release lists SHA-256 checksums for its files.

Unofficial. This page is written by an independent directory. It is not made by, endorsed by or affiliated with Aerosoft (developed by MR-Software) or openOMSI.org (created by usonskyyyy; lead developers thibautgnt and isaacsa2) (openOMSI (OMSI 2 rewritten in Rust)'s author). We do not host any files, and we never link to game files, ROMs or ISOs.