I want links that I open (in Firefox, from Firefox, like opening any normal link) to open in the same tab (unless otherwise specific, like a normal browser should work), and all links from other applications to open in a new tab. Whenever I click a link, it overrides my current tab, even if I'm working on something important. Apps do not always make it obvious what might be a URL. Windows for instance LOVES to open up "support" links in your browser. Firefox also does this itself with its update function, it opens up its update notification by overwriting your previous tab. This is a really, really basic feature that should really be a default setting, but it doesn't seem to exist in settings at all.