A thing that shocked me as I was working on the text editor was how capable modern terminal emulators are when you account for ANSI extensions. First-class clipboard access, mouse events, precise text styling, focus tracking, system notifications, key press/release events, etc. are all possible with a modern terminal emulator. There's not really anything else you need to build a very competent, ergonomic editor UI.

You can even use tools like trolley to wrap the entire application up in a ghostty-powered shim that presents the application as a native UI application: https://github.com/weedonandscott/trolley