I think @elauso@feddit.de did a better job explaining it… It’s a rewrite if you’re trying to create the same product as before. And that’s not what Wayland is trying to do.

I mean we also don’t say a car is a rewrite of a train (or vice versa) but they share some of the same components (wheels, seats, a driver…) And libinput, drm, mesa aren’t copied to the source code. They’re seperate projects and components/libraries that are used via an interface that makes them reusable. Lots of other projects also use the same set of libraries. For example networking. Or games that are built with the same game engine.