Orion - Ultima Online graphic client, using OpenGL for rendering
C++ CMake Objective-C C Other
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.


OrionUO Client

Travis Build Status Build status

  • OrionUO Client - is an alternative, open source Ultima Online graphic client.

  • Platforms: Windows and Linux (in progress)

  • Rendering: OpenGL 2.0 and higher

Orion Community




Our Mantis bugtracking system or github issue tracking


Other Orion Projects

Building OrionUO

This project requires CMake 3.7 to build. It currently supports Visual Studio 2015, 2017, GCC 7.0 and Clang 6.


On Windows, to generate the Visual Studio solution, go inside your cloned OrionUO folder and do:

md build
cd build
cmake -G "Visual Studio 2017" ..

This will build a 32bits executable. If you do want 64bits, you can do cmake -G "Visual Studio 2017 Win64" .. instead. Note that plugins are still unsupported in the 64bits client.

Or, you can use CMake-GUI to configure and generate the solution.

  • If you want to help converting OrionUO to SDL, you can disable ORION_WISP option in CMake. This option enables the original client implementation in pure win32 API and is kept as a reference implementation to use during the client conversion to SDL.

Linux (in progress)

$ mkdir build
$ cd build
$ cmake -G Ninja .. -DCMAKE_BUILD_TYPE=Release
$ ninja OrionUO_unity -j8
$ ./OrionUO/unity/OrionUO

You'll need a Client.cuo and a uo_debug.cfg in the working directory. Inside uo_debug.cfg you can add a line CustomPath=/path/to/uo/data, so Orion will be able to find your original client data files.


See the project planning here to find tasks on which you can help.

More detailed contribution documentation soon


Hotride (Author)


and Others

Support this project, make a donation!


WebMoney: R644829964694 Z983232789532 E400319624386