Ultima Online, though it gets patches and new expansions fairly often, so don't know if that counts.
The oldest, unupdated app would probably be AutoCAD 2000. I don't use it that much, but whenever I want to plan something like furniture placement, or where I'd like to build a wall, I'll use it. I tried the latest autocad and I was not impressed. 2000 is just more user friendly and intuitive. 2009 (I think that's the latest) is very flaky and jumpy, and 3D stuff is messed up.