The new version of Mozilla Firefox is out but I stongly recommend not using it as your primary browser just yet. (I’ve learned this the hard way.) The main reason is that none of the extensions work yet. (They’re all being tested for compatibility first.) If you do install it, you cannot install it over a previous version. You must uninstall the previous version first or install it into a new directory. One significant improvement though is that this new version does import settings and bookmarks from previous versions, Mozilla, Navigator, and Internet Explorer.