Horizon vs openOMSI
Horizon and openOMSI are both game engine software. Horizon is open source under MIT, with 6.1k GitHub stars. OpenOMSI is open source under AGPL-3.0, with 739 GitHub stars.
Which to pick
- Pick Horizon when
- You are curious about a faster Minecraft-compatible client and comfortable with alpha software.
- Pick openOMSI when
- You own OMSI 2 and want a 64-bit, multithreaded engine with a modern renderer that keeps your installed mods.
Side by side
An unofficial from-scratch rewrite of Minecraft: Java Edition in Rust, checked for identical behaviour against the original game with differential tests.
A from-scratch Rust recreation of the OMSI 2 bus simulator that loads your existing OMSI 2 maps, buses and mods. It has a launcher, LAN multiplayer, a dedicated server, VR and builds for Windows, macOS, Linux and Android.
Created in October 2026, unofficial, and could face legal or compatibility problems with Mojang.
Early development with expected bugs, and it will not start without a licensed copy of OMSI 2.
Experimental (both)
Desktop app
Desktop app and mobile app
Rust, wgpu and Vulkan
Rust, wgpu, Lua and WebAssembly
Open source, MIT (permissive)
Open source, AGPL-3.0 (network copyleft)
You can build it into a product you sell, as long as you keep its copyright notice.
Use inside your business is unrestricted. If you change it and let customers use it over the internet, you must publish your changes.
6.1k GitHub stars
739 GitHub stars
New: started 1 month ago, latest release v0.2.97.
New: started 1 month ago, latest release v0.3.45.
Other comparisons
More game engines
Both sides were judged on 2026-11-03 from each project's README and GitHub data. License, age and popularity lines are worked out directly.