The text-based UI reminds me of the Acme text editor from Plan 9 (it’s now also available for other OS so easy to try) :
From "Acme, A User Interface for Programmers"[2] by Rob Pike:
> Cedar was, however, the major inspiration for Oberon [Wirt89], a system of similar scope but much smaller scale. Through careful selection of Cedar’s ideas, Oberon shows that its lessons can be applied to a small, coherent system that can run efficiently on modest hardware. In fact, Oberon probably errs too far towards simplicity: a single-process system with weak networking, it seems an architectural throwback.
> Acme is a new program, a combined window system, editor, and shell, that applies some of the ideas distilled by Oberon. Where Oberon uses objects and modules within a programming language (also called Oberon), Acme uses files and commands within an existing operating system (Plan 9). Unlike Oberon, Acme has does not yet have support for graphical output, just text. At least for now, the work on Acme has concentrated on producing the smoothest user interface possible for a programmer at work.
[1]: http://www.bitsavers.org/pdf/xerox/parc/techReports/CSL-83-1...
[2]: https://www.usenix.org/legacy/publications/library/proceedin...
[0] in fact, he's said he built the FPGA Oberon[1] because his favourite mouse[2] was a departure gift from PARC, but of course, he can't buy any system today that would allow him to keep using it, so he built one. Now that's a yak shave.
[1] https://news.ycombinator.com/item?id=32606760
[2] I've seen a not-still-in-use wooden mouse from the Englebart days, but I believe Bucky's is plastic.