[Tuna-Fish]

The only part that's big enough and self-contained enough to be worth reusing in a Haskell project would probably be the cursor handling. For all the rest, writing the wrappers necessary to deal with them from Haskell would probably be a bigger job than just re-implementing.

The whole point of Wayland/Weston is that the display server is miniscule. All the complex parts are reimplemented in other parts of the stack already, so just let them deal with them and hand over pointers. It's so small that if there ever is a Haskell version of it, I expect it to be formally proven to be bug-free.