I'd start with the core TECO editor I've written in Free Pascal[1]. Free Pascal does gigabyte strings you don't even have to allocate. Then I'd read the Emacs

I'd start with the core TECO editor I've written in Free Pascal[1]. Free Pascal does gigabyte strings you don't even have to allocate. Then I'd read the Emacs manual, and start writing code and tweaking TECO to make it all impedance match better. But I'm old and weird, so maybe not the best way to get there. [1] https://github.com/mikewarot/teco https://github.com/mikewarot/teco