Re: What is the URL for the Mozilla Firefox start page? This is the Google/Firefox home page with the Google search, which is the new version built into Firefox.
The http://www.google.com/firefox used to be the old Firefox start page for 3.6.* and earlier and has not been maintained by Google ever since Firefox 4.0 came out as to why this start page may have the "You're not on the latest version of Firefox" message at times.
The default homepage ever since Firefox 4.0 has been about:home