OpenMW (for TESIII:Morrowind) is amazing. Strictly an improvement on the original. Far more stable—I finished the main campaign and several major side quest trees with a bunch of mods active and experienced zero crashes, which is unheard of with the original engine—and somewhat better-looking. Runs just about everywhere. It's great.
Yes -- install Morrowind from Steam, run it once (to make sure registry keys and the like are set up correctly), and then the OpenMW installer will copy the files it needs to run out of the existing MW installation directory.
