Without knowing about Jef Raskin's ideas, I implemented something really similar to one of them in one of my Mac apps, Superkey. This idea in the Canon Cat was that you hold down a key and type text that you want to select anywhere in a document, then let go to select it - typically faster than reaching for a mouse or hitting arrow keys. In the Canon Cat it was an additional key (the leap key), below the space bar.

For the implementation in Superkey, you can select a key to use for this, like caps lock. The way I use it is I hold the caps lock key and type text, then the app uses OCR and optionally the macOS Accessibility API to search for matching text. Releasing the key or hitting enter will click (or double or triple click, etc) on a match.

Raskin's idea was of course more text-editing focused, and tapping on the leap keys will also move the cursor. I typically use Superkey to navigate UIs quickly, kind of as though UIs all have keyboard shortcut navigation. There are also limitations that Superkey faces, like not having access to offscreen parts of a document.

Ha ha ha, suckers! I still have my Canon Cat from '87 and use it most days. I don't have to use emulation!

Seriously though... I did a contract for Jef in the early 80s and he showed me the Swyft card. Was happy to buy one of these things when it hit the shelf (though figuring out where to buy it from was kind of difficult.)

The keyboard doesn't have as good a feel as you might expect, so emulation will let you use a decent, modern keyboard. I still have a large box of floppies so that's not an issue. In the 90s I hacked together some FORTH code to read / write documents over the serial port, but it's a bit fragile.

Anyway... It's worth checking out. The only thing I would change would be up and down arrow keys. I think Jef had a philosophical problem with this which is why it never shipped with them. It's usable without them, it just seems a bit weird.

Surprised the article didn't mention the book "The Humane Interface" which was the book Jef wrote with the philosophical underpinnings of Swyft and IA/Canon Cat. Worth a read. Might be up on the Internet Archive.

A shame THE/Archy and RCHI aren't mentioned!