And you can left click and middle click the maximize button on a window title bar to maximize it on the vertical and horizontal axises only. Combined with edge snapping making it easy to move a window on only one axis at that point, you can set up a few column tiles that way very easily.

Funny memory: I've been a KDE developer for 12 or 13 years. I think one of my first patches ever was a fix for the window manager to restore to correct window geometry when cancelling a partially maximized state using the restore action. A friend of mine was using the above feature to set up tiled text editors and I wanted to fix it for him.