[Pharo-users] ProfStef or HelpSystem ?

Hi all, What are the differences between the two systems ? From what I see, a ProfStef lesson is a collection of pages with buttons to navigate between them. Help System seems to be same except that it can have a hierarchy of pages and is more 'textual' than a ProfStef lesson (the absence of syntax highlighting confirms that?) Now I don't see why there are two different browsers/systems ? Sorry if I'm missing something evident :/ Francois