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.

X:UO Assist

Currently the only closed source component, X:UO Assist is a full featured game assistant with macro and scripting support.

Making use of the powerful Qt scripting, a Javascript based scripting engine, X:UO Assist is extremely flexible enabling complex actions to be easily automated.

Check the scripting documentation for more details.



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


Ubuntu 16.04 LTS (64bits) or newer;
Manjaro Linux 18.02

Distribution provided SDL2.0.4+, OpenGL, GLEW 1.3+, Qt5 and Qt5Script
Make sure to install these dependencies via your package manager!


MacOSX 10.13 or newer

SDL2, OpenGL and GLEW

Install Instructions

Ubuntu 18.04
$ sudo apt install libqt5core5a libqt5multimedia5 libqt5script5 libglew2.0
$ sudo ln -s /usr/lib/x86_64-linux-gnu/ /usr/lib/x86_64-linux-gnu/
Ubuntu 16.04
$ sudo apt install libqt5core5a libqt5multimedia5 libqt5script5 libglew1.13