Related to https://lobste.rs/s/d4nhli/writing_editor_less_than_1000_lines_code (antirez’s post about the text editor under discussion with this post)
I like this style for reading code. It’s seems to be a hell of a lot of work for the author, though.
Agreed. The presentation is impressive.
There’s also an old but really interesting tutorial on how to write a text editor on Windows from scratch. Even if you never plan on writing anything for Windows proper, the same general techniques and issues would come up if you were building a similar component on bare Gdk or Cocoa, so it can still be fun reading. (And if you do write for Windows, an interesting exercise would be to port the text rendering code to Uniscribe to get better i18n support.)