Comment by qwertox

Notepad++ (and this one here) are based on Scintilla [0]. It's worth pointing it out because it is a high-quality open source code editor component.

SciTE [1] is the "official" demo-editor for Scintilla and was last updated on March 9th 2024. The history reaches back to 1999.

[0] https://www.scintilla.org/

[1] https://www.scintilla.org/SciTE.html