I need some facts, does K-Melon use some portions (for example libaries)
from IE 5.x, like Outlook Express, or could i just install and use it like Opera
on my System?
You will need one of the Common Control Libraries for IE 5 if you don't have IE installed on your machine at all. There's a link to that in the Release Notes.
Actually, you don't *need* any bits of IE (read: updated system components) on your system. The rebar menu is the only thing that needs the common controls update, so if you're willing to go without the nice toolbar/menu combo, you won't have to update anything.