The First Tiling Window Manager - Siemens RTL Tiled Window Manager (released in 1988)
Channel: wis
Date: 2019-06-10

* not the first, but it was the first to have features that we now expect to see in what we now call a "tiling window manager".

the first, most likely was at Xerox PARC
https://en.wikipedia.org/wiki/Tiling_window_manager#Xerox_PARC