Eine Firefox Toolbar Entwickeln
Ok das ist ja nichts neues aber hier ist mal ein zusammengefasster Artikel wie das geht.
We will create a Firefox extension to find all links in the current web page, highlight those which have a target attribute and alert you how many links it found. The good part is that once you have done this, you have both an understanding of Firefox extension development as well as a blueprint for any extension you would want to develop in the future.
How to develop a Firefox extension
banana out.