<p align="center"> <a href="https://muo.gg"><img alt="ModernUO - Ultima Online Server Emulator for the modern era!" src="https://cdn.muo.gg/gh/muo-logo.svg" width=128px /></a> </p>

ModernUO

Ultima Online Server Emulator for the modern era!

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Requirements

Supported Operating Systems

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Required Frameworks

All Operating Systems

Windows

Development

Supported IDEs

<p align="left"> <a href="https://www.jetbrains.com/rider/download"><img height="64" title="Jetbrains Rider 2025.3+" alt="Jetbrains Rider 2025.3+" src="https://cdn.muo.gg/gh/jetbrains-rider.svg"></a> <a href="#"><img alt="space" width="32" src="https://cdn.muo.gg/gh/space.png"></a> <a href="https://code.visualstudio.com/download"><img height="64" title="VSCode" alt="VSCode" src="https://cdn.muo.gg/gh/vscode.svg"></a> <a href="#"><img alt="space" width="32" src="https://cdn.muo.gg/gh/space.png"></a> <a href="https://visualstudio.microsoft.com/vs/community/"><img height="64" title="Visual Studio 2026" alt="Visual Studio 2026" src="https://cdn.muo.gg/gh/vs2026.svg"></a> </p>

Getting Started

• Install prerequisite requirements
• Clone this repository (or download the latest):
  • git clone https://github.com/modernuo/ModernUO.git
• Open ModernUO.sln to start developing

Building/Publishing

Interactive Mode (Recommended for new users)

Run ./publish.cmd (Windows) or ./publish.sh (Linux/macOS) with no arguments to launch the guided build tool. It will:

• Check prerequisites (.NET SDK, native libraries)
• Walk you through configuration and platform selection
• Build and publish the server to the Distribution directory
• Show deployment instructions for cross-compiled builds

Command Line

./publish.cmd [release|debug] [os] [arch]

• os - Supported operating systems
  • win - Windows
  • osx - macOS
  • linux - Linux
• arch
  • x64 - Intel/AMD 64-bit
  • arm64 - ARM 64-bit

Linux Prerequisites

Fedora, CentOS, RHEL, etc

dnf upgrade --refresh -y
# CentOS does not come with EPEL enabled
dnf install -y epel-release epel-next-release
dnf install -y findutils libicu libdeflate-devel zstd libargon2-devel liburing-devel

Ubuntu, Debian, etc

apt-get update -y
apt-get install -y libicu-dev libdeflate-dev zstd libargon2-dev liburing-dev

OSX Requirements

brew install icu4c libdeflate zstd argon2

Running the Server

• Follow the publish instructions
• The Distribution directory is portable — copy it to your production server for deployment
• Run ModernUO.exe or dotnet ModernUO.dll from the Distribution directory
• On first run, the server will prompt you to configure game data file locations

Troubleshooting / FAQ

• See FAQ

Want to sponsor?

Thank you for supporting us! You can find out how by visiting the sponsors page.

Collaborators

Thanks

• RunUO Team & Community
• Voxpire, the ServUO Team & Community
• Karasho, Jaedan and the ClassicUO Community

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<p align=center>Development Tools & Plugins provided with &hearts; by<br/><br/><a href="https://www.jetbrains.com/?from=ModernUO"><img src="https://cdn.muo.gg/gh/jetbrains.svg" height="64px" alt="JetBrains" title="JetBrains" /></a><br/> <a href="https://material-theme.com/"><img src="https://github.com/AtomMaterialUI/material-theme-issues/raw/master/logo.svg" width="64px" alt="Material Theme" title="Material Theme"></a></p>