Reverse-engineering the 1998 Ultima Online demo server

[Diablo]

In any MMORPG, the average user will generally only encounter the client side of the system. This makes building a compatible open source version of the proprietary server into a bit of a chore. Of course, sometimes you get a bit of a break, such as with the – still active – MMORPG Ultima Online, when the disc for the 1998 The Second Age expansion contained a stand-alone demo. This also meant a (stripped-down) server which has been gratefully reverse-engineered by the community, with [draxinar] now claiming to have made the most complete server based on this demo server.

To make things extra challenging, the originally written in C++ server binary was reverse-engineered into C99 code, meaning that the use of classes and associated vtables had to be left intact, just without the critter comforts provided by C++.

The total process took about a decade with occasional progress, with the current server binary being mostly identical to a 1998-era Ultima Online server. Some features that were stubbed out or disabled in the demo server had to be re-enabled or reimplemented, including the user account system.

Features that were left out of the final release like the ecology system were also enabled in so far as they were implemented. Although there is probably still a lot more work to be done on the code, [draxinar] reckons that this is a good point for the community to get involved to do some testing and provide feedback. There are also some missing server-related resource files that may still be saved somewhere.

Thanks to [adistuder] for the tip.