DOSBox-X

The DOSBox situation is so unusual. There hasn't been a new major release since 2010, and nothing at all since 2019. And yet it's still being sporadically worked on, so it's not entirely dead.

To fill this void, there are three competing forks with different approaches. And they've all been going for years, they haven't fizzled out. I can't think of anything else like it in the emulation scene or really anywhere.