Structure editing for Pascal, c. 1986. This video was recently produced by an enthusiast running the system in emulation.

Fascinating! Also a good reminder that even the newest and shiniest hammer is not a great screwdriver. I'm referring to the system's love for mouse interactions.. 🙂

The generally poor UI of this editor is also one of the many answers to the question of why structure editing didn’t take off outside the Lisp world.

actually I like it, menu navigation is not so great, but the idea is great and I am kinda rediscovering same approach

(To be clear, I strongly prefer structure editing and use it every day.)