Notepad++ is a well-known application which is just a notepad, but much more powerful than standard “notepad.exe”.
It’s very useful as a quick note placeholder or simple code editor. It can colour the syntax in many different languages, has tabs and regex search functionality. I appreciate it for nice performance and additional plugins.
I mainly use it as a place for short notes, tasks to do or XML editor.
Below sample XML file with coloured syntax and formatted using XMLTools plugin:
Below sample c# file with coloured syntax and find box:
Check this out: https://notepad-plus-plus.org/