I've been implementing and using vertical tabs since around 1988, with I released a commercial product with tabbed windows, the NeWS version of UniPress Emacs, and used it to develop a hypermedia authoring environment for HyperTIES at the UMD Human Computer Interaction Lab.

https://en.wikipedia.org/wiki/Tab_(interface)#/media/File:Hy...

Vertically tabbed windows combine synergistically well with pie menus, and are great for window management, especially when you have many windows.

They are purposefully NOT patented, since the idea is so fucking obvious, but it's disappointing they took so many decades to catch on finally. Still there aren't any decent desktop window managers I know of that implement tabs the right way. (tvtwm is not the right way!)

The later NeWS Toolkit versions from the early 1990's let you drag the tabs around to any side of the window you like: left, right, top or bottom, to any position along any edge. The user should be able to decide which edge and where the tabs are attached to for each window, it should not be hard wired like the tabs in VSCode and web browsers typically are. Being able to choose which edge the tab is on and where the tab is gives users better more flexible ways to organize and manipulate their windows.

https://en.wikipedia.org/wiki/Tab_(interface)

HCIL Demo - HyperTIES Authoring with UniPress Emacs on NeWS, tabbed windows, pie menus:

https://www.youtube.com/watch?v=hhmU2B79EDU

I had a video of the NeWS tabbed windows, demonstrating dragging the tabs to different window edges, but youtube took it down because it contained copyrighted music (Herbie Hancock's Rockit).

Oh, here's the original video you can download from my server:

https://donhopkins.com/home/movies/TabWindowDemo.mov

Here are some different version from 1988-1991 for different versions of NeWS:

https://donhopkins.com/home/archive/NeWS/tabwin.ps

https://donhopkins.com/home/archive/NeWS/tab-1.ps

https://donhopkins.com/home/archive/NeWS/tabframe-1.ps

https://donhopkins.com/home/archive/NeWS/tab-3.0.2.ps

Here's another NeWS program that uses vertical (by default, but any edge if you want) tabs on windows around PostScript objects that you can push and pop on the stack with "direct stack manipulation":

The Shape of PSIBER Space: PostScript Interactive Bug Eradication Routines — October 1989

https://donhopkins.medium.com/the-shape-of-psiber-space-octo...

PSIBER Space Deck Demo:

https://www.youtube.com/watch?v=iuC_DDgQmsM