If you're old enough to remember Theme Hospital, chances are you also remember the Neverhood -- a claymation point-and-click adventure game. Just like TH, the game has been abandoned by EA with no chance of a comeback.
However, the creators of the game are teaming up to create another adventure game with the same kind of style and heart, Armikrog. And this time, they're not selling the rights to it to anyone. They're running a Kickstarter campaign to get the game made, so if you're a fan of the Neverhood, this might interest you: http://www.kickstarter.com/projects/1949537745/armikrog
It seems that it won't be open-source, but it will be cross-platform, DRM-free, and the creators will keep the rights, so it's likely it won't become abandonware.