[koprulusector]

This is how modern X applications look by default. It’s gtk, compositors, and window managers that add/change the aesthetics.

[josephcsible]

If you're just running an X server and a single program, I thought you didn't get any decorations at all.

[asveikau]

Window decorator has a specific meaning in X terminology, referring to the frame of the window done by the window manager.

The screenshots are using some commercial Unix wm (mwm?) or one of the free ones that copies their look (fvwm?)

I use fvwm on one of my machines in 2023, in part because I found myself on a retro kick a few years ago, so I don't think it's that weird, though it is extremely dated.

[LeFantome]

Super fast and light.