Java Embedding Plugin allows web browsers other than Apple's Safari to use the most recent versions of Java on Mac OS X.
The Java Embedding Plugin has been bundled (application: ~/Contents) with current Mac distributions of all the Mozilla.org browsers--Firefox, Seamonkey, and Camino--as well as Flock among others.
If you're using one of these browsers, you may wish to replace the bundled version of the Java Embedding Plugin with a more recent version.
[Perhaps share between all browsers from /Library/Internet Plug-Ins/]
When used together with an updated version of Mozilla's MRJ Plugin Carbon (included in the distribution), the Java Embedding Plugin's functionality is available to recent versions of Firefox, Seamonkey, Camino and Flock. But in principle any web browser (e.g. Songbird) could use one of the Java Embedding Plugin's two APIs to add support for Java 1.4.X, J2SE 5.0 and Java SE 6.