Reading code with no syntax highlighting or indentation is more painful than I thought.

can recommend notepad++ portable. i always have it on my side 🙂
if it fits your language...

Back in the days, I used notepad.exe to code

@gunslinger same here but notepad and highlighting ide are what a flintstone and a match are to firestarting

It was a template file with php code in phpstorm. Adding the php tag temporarily gave me syntax highlighting and I could change it in the settings too. But I tried just reading it without at first, which was not a good idea.