To be honest, I'm completely of the opposite opinion. Backwards compatibility means I don't have to rewrite anything again and again and again. Compare with g

To be honest, I'm completely of the opposite opinion. Backwards compatibility means I don't have to rewrite anything again and again and again. Compare with gtk, which breaks backward compatibility liberally. After a few versions, old applications stop working unless someone takes the time to fix them. This means application progress is reset again and again. We lose tons of old code for no good reason. OTOH, the old tools written in win95's win32 or in x11's xlib (or posix, mother of all stable APIs), still work 20 years later. This means you can focus on improving instead of rebuilding. Don't get me wrong: Backwards compatibility is a cost. But I'd rather have to pay it once, centrally, instead of distributed over all applications. Very rarely you can deprecate and fix a small part. But in general, libraries are the ground upon which applications are built. That ground should be stable. BTW, I fear the damage wayland will do to the linux ecosystem.