Comment by kelnos

(xfwl4 author here.)

> I wonder how strictly they interpret behavior here given the architectural divergence?

It's right there in the rest of the sentence (that you didn't quote all of): "... or as much as possible considering the differences between X11 and Wayland."

I'll do my best. It won't be exactly the same, of course, but it will be as close as I can get it.

> As an example, focus-stealing prevention.

Focus stealing prevention is a place where I think xfwl4 could be at an advantage over xfwm4. Xfwm4 does a great job at focus-stealing prevention, but it has to work on a bunch of heuristics, and sometimes it just does the wrong thing, and there's not much we can do about it. Wayland's model plus xdg-activation should at least make the focus-or-don't-focus decision much more consistent.

> I am curious about the mandatory compositing overhead. Can the compositor replicate the input-to-pixel latency of uncomposited x11 on low-end devices or is that a class of performance we just have to sacrifice for the frame-perfect rendering of wayland?

I'm not sure yet, but I suspect your fears are well-founded here. On modern (and even not-so-modern) hardware, even low-end GPUs should be fine with all this (on my four-year-old laptop with Intel graphics, I can't tell the difference performance-wise with xfwm4's compositor on or off). But I know people run Xfce/X11 on very-not-modern hardware, and those people may unfortunately be left behind. But we'll see.