I like the idea of X forwarding, but it doesn't work in real world anymore. As far as I know, it has to do many round-trips for everything. Launching something like LibreOffice Writer is funny, it will be loading bit by bit, icon by icon for several minutes. It was only usable for me on < 1ms network.

Unlike say VNC, it opens windows locally.

And now there's Waypipe which does the same thing, but for Wayland. And it actually works! Even better than VNC.

BUT, it doesn't work for X programs. It can somewhat work with rootful Xwayland... but that's basically a desktop for X-only programs.

Welp, I just wanted to check something on the remote desktop, so I launched VNC, and WOAH, I didn't expect to get XFCE invasion.
I didn't know XFCE can do Wayland now.

Anyway, this cursed thing does actually work pretty fine. xfce4-session works with Waypipe, good to know.

I'm guessing that your remote XFCE isn't doing anything to do with Wayland, it's the local VNC client.

No, I was not using VNC. VNC xstartup script just launched xfce4-session which connected to Waypipe rather than Xtigervnc.

It does integrate itself to KDE nicely. Even with virtual desktops. And it even properly does the animations. Downside is, I can't access the original desktop on my laptop while it's running. Peek at desktop also shows XFCE.
Here's the cube switcher, showing XFCE instead:

If you think this is cursed... Try playing steam games over X forwarding xD

It's cool though!

Only if the machine is on LAN. I am running with 250ms here.

I was referring to this part:

Welp, I just wanted to check something on the remote desktop, so I launched VNC, and WOAH, I didn’t expect to get XFCE invasion.
I didn’t know XFCE can do Wayland now.

Now I don't really understand what you're doing at all.

Using Waypipe, which proxies Wayland program GUIs to my local computer, just like ssh -X, but with Wayland, and it actually works over the internet (read: high latency).

I didn't know XFCE supported Wayland , so I casually ran vncserver, which launched xfce4-session, except that it attached itself to the Wayland display (proxied to my local machine) rather than X display of TigerVNC. And here come the full XFCE right to my local machine (which is running Plasma).

What debarchery!

just like ssh -X

No, that's not what's happening. X11 forwarding is telling the server to treat a TCP socket as a display, and after passing xauth, the frames are just shoveled into an ssh session. Waypipe is serializing Wayland messages so they can be redirected to multiple portals, specifically over a socket. They don't really work the same at all.

I didn't know XFCE supported Wayland

Some parts of xfce do, xfwm4 does not.

so I casually ran vncserver, which launched xfce4-session

This is because your vnc is configured to do so.

except that it attached itself to the Wayland display (proxied to my local machine) rather than X display of TigerVNC. And here come the full XFCE right to my local machine (which is running Plasma).

This part doesn't make a lot of sense.

If invoking xfce4-session works, it means you are doing so over vnc, not waypipe.

Sorry about my Waypipe misunderstanding.
vncserver I configured that way, so of course. I just didn't expect it to connect to Wayland.

If invoking xfce4-session works, it means you are doing so over vnc, not waypipe.

It does work over Waypipe. You can even see in my screenshot that on the remote machine it shows Waypipe as the WM.
The remote is running Debian 13, with multi-user.target set as default target to keep the GUI from starting. XFCE version is 4.20.1.

I've used Xpra for similar