Plaintext highlighting

[Julius Hamilton]

Hey,

I would like to highlight man pages just to comprehend them better.

Can anyone recommend a most widely used, reliable highlighting tool?

I was thinking Emacs Org Mode but after looking at the docs it seems like
it might not be easy to select many regions of text and enter a tag to
highlight the text. It would be better if there was just a cursor you can
move through the text to select region after region for highlighting (in
various colors).

Can anyone recommend a tool like this?

Thanks very much,
Julius