When we have to mark a pdf (colouring the text like in the old student times) we can use any pdf editor
In the web and under FF with wired-marker or many other addons.
In a doc with a text processor
Obviously is not so easy to mark in a txt file, or in a html set downloaded to our pc.
How can I mark a HTML file downloaded ?
I am thinking in an application specially designed to mark all types of files or possibilities. The first care I supposed must be the position of the file in the pc (if you change the folder). I suppose is possible with an auxiliary database to control all marks.
Do you know any application with universal purpose or for some types of files ?