This is an add-on for highlight selected text like a marker. This is a study for DOM2 Range.
Ver.2.0 or later can remember markers you set, for each webpage.
If you see any problem, see FAQ at first. If there is no solution, post a report to the issue tracker on the GitHub please.
If you use Mozilla Suite or Netscape 7, see How to install and update? (contains important notes) and How to uninstall by hand?
When the context menu opened with a selection, the menu of Line Marker is available. How to customize markers? See the file "linemarker.rdf" in the profile folder. It is automatically created by this extension.