Most code editors are similar to notepad.exe in that they are "text editors", but unlike notepad.exe they have functionality built into them to send the code into the compiler.

Espresso is a gorgeous Mac-only code editor that’s powerful and smooth, like the caffeinated beverage it’s named after. This ...

Notepad now allows you to write Markdown without installing anything extra. Use toolbar shortcuts to apply formatting, switch views, and clear formatting when needed.