In 2012 a team of eight modders went to work on a frighteningly ambitious project: rebuild The Elder Scrolls III: Morrowind using the Skyrim graphics engine. Fast forward to 2014 -- and now incorporating a team of 30 modders -- and the Skywind Project is looking mighty fine. This isn't just a one-to-one porting of old Morrowind. Skywind is a complete rebuild of Morrowind from the ground up.
You can download the Skywind Project right now, though it's still a work in progress, and mainly for landscape exploration and very basic environmental interactions. There's a ways to go toward completion. But this official development video depicts some of the monumental progress the team has made so far.