CrossUO: Ultima Online

The True Open Source Ultima Online Client

About the Project

CrossUO is an Open Source Ultima Online® client - a hard-fork from OrionUO, ported to Linux and MacOSX by fungos. The project is currently maintained by fungos, Deuce and Nirad.

The project aims to have a fully open cross-platform Ultima Online® client compatible with different eras from the game.

The CrossUO Suite is composed of the game client, the game launcher and updater and (for the foreseeable future) a closed source scriptable game assistant similar to Razor.

X:UO Launcher

A full featured game client account manager, launcher, configurator and updater that will keep you up-to-date with all X:UO Suite applications for your platform!

Cross-Platform Client

CrossUO is a OpenGL and SDL2 based game client reimplementation that tries to be compatible with original clients from all Ultima Online® eras.

Currently supporting Windows 7, Windows 10, Linux and MacOSX.



Windows Installer
Windows 7, 8 or 10 (64bits)


Ubuntu 16.04 LTS (64bits) or newer;
another recent Distro.
Note: to use X:UO Assistant, Qt5 with multimedia and script support is required.
Example: sudo apt install qtmultimedia5-dev qtscript5-dev


MacOSX 10.13 or newer