I know that some old Netscape products included a Java runtime environment (JRE).
(I'm not sure where to download the most recent app with that integration, I'll continue to look. http://www.oldversion.com/Netscape.html excludes Mac so maybe http://sillydog.org/narchive/ …)
Netscape aside: does any other browser – one that will run on Mountain Lion – include a browser-specific JRE that will run on Mountain Lion?
Whilst it's desirable to have a JRE that is current and supported, for this question I'm less interested in the version of the JRE.