Hmm.. I *think* I understand what you want. I suppose there might be a way to get the information out of Mozilla, but probably not just with Perl and not without a lot of study.

I expect the best way would be to build your own web browser and not try to stick a button into Netscape. So you have to write a browser, and somehow render the page which is very hard to do well, unless plain text is enough for you.

It seems that HTML and LWP modules would be useful for writing a text-only version, and you could run this inside a GUI window if you like but you will not be gaining much in the way of functionality by using a window unless you have something special on your mind about which we don't know.

Perhaps someone knows about some magical dll that will do what you want but generally I'd say this is not a case that Perl will be able to enhance your current experience of using Internet Explorer with that software as-is. Please be a bit clearer about what exactly you want to do since it is a little confusing what you mean by "browser".

Also it seems that if you only display links which are new, you are going to be unable to read a lot of pages that have links embedded in the text, like PerlMonks. Perhaps you want not to remove data, but to add data to the page so as to give you more information about the connectedness of the pages you are browsing?