Uh ... Netscape (and, mind you, I used to be a "Netscape guy", so I'm not mocking) went into it's "terminal release" two years ago (Netscape Navigator 9, which was based on FireFox 2), and is no longer being supported!
Of course, being as "oldskool" as I am, I'm always heartened to see sites that make use of "JavaScript, Tables, Cookies and Frames" instead of CSS/PHP/AJAX/whatever, but it's funny to see MSIE and Netscape listed as the ones suggested ... maybe they're worried that one of these days W3C is going to actually pull the plug on all that "deprecated" HTML code and then folks will NEED a copy of Netscape!