OpenMW has been on my list to try out for a while now, I should have thought of that one. I hadn't heard of OpenGothic, but I also only recently started learning about that game at all with the remake coming out soon, so I might need to add that to my list as well!

This makes me think, is there one of those "awesome" lists for open game reimplementations? If not, someone should make one...

(edit: Thanks for the multiple great replies on this! Now I have even more stuff to go through to add to my lists, and I love having that problem)