My personal editor MySample [1] is an extension the Crystal Edit [2] control. Through the years I have improved the colour coding, added navigation through HTML files (for editing my static website), to also make it possible to open images and added a small scripting language, primarily to manipulate images.

[1] http://iwriteiam.nl/MySample.html

[2] https://www.codeproject.com/Articles/272/Crystal-Edit-syntax...