This page is for a very specific type of keyboard key which has a small display integrated within it. Thus, they don't even run an operating system and almost certainly do not feature a noteworthy CPU, which eliminates the need to list those.

While this hack is very “face-value”, this is still an interesting little feat. Apparently, these little keyboard keys can be used as independent displays to run games, like DOOM.

https://www.youtube.com/watch?v=q7b9glYuAXw