OUO

About

Ultima Online is a fantasy MMORPG released by Origin Systems on September 24, 1997. OUO is a full reimplementation, in standard C99, of the Ultima Online server found in the Ultima Online Demo that shipped with the first release of Ultima Online: The Second Age. It aims to run the game as closely as possible to the original server as it was around June 1998. It has been ported to POSIX systems, tested mainly on Linux, and builds as 32-bit or 64-bit.

How it differs from the original

Unlike the original demo server, OUO accepts client versions 1.25.30 through 5.0.9.1, and it restores subsystems the demo left stubbed out, including account management, periodic world saves, NPC predator/prey AI, in-game chat and three skills added in 1999. A "-features none" flag turns off these additions for behavior that matches the original binary.

Getting started

Build and installation instructions are included in the repository, and the server data lives in a separate companion repository. The developers recommend connecting with a Renaissance-era client such as 2.0.7. A public test server is also available.

History

The project builds on the UO:98 project that Batlin and Derrick started in 2011. OUO takes that work further by rebuilding the whole server source through reverse engineering of UoDemo.exe.

Known issues & limitations

• compatibility: Tested mainly on Linux; other POSIX operating systems should be supported but are not fully verified.

Credits & contributing

• Contributors disassemble functions from UoDemo.exe and rewrite them in C, noting each function's original binary address in a comment.