A free open source server emulator intended to provide solid baseline code for others to base their own development on.

A highly scriptable open-source server emulator, capable of running on various platforms.

A Microsoft.NET server, with the goal of being easy to use.

Specializing in information and tools for creating custom maps.

Official home of the sphere software and client.

Open-source C# UO server software package. Easy to use, yet still very powerful.

Home of Pandora's Box, a popular GM tool for RunUO. Also offers some other RunUO utilities.

Resource and news information page for UOX3.

An encryption removal tool, required for logging in to most emulators.

Home of the classic branch of UOX, without the Javascript engine.

Wolfpack is a free Ultima Online Server Software, easy to use and script.