Added in jQuery.browser.firefox, deprecated jQuery.browser.mozilla.

src/core.js

@@ -620,7 +620,7 @@ jQuery.extend({
 		return ret.concat.apply( [], ret );
 	},
 
-	// Use of jQuery.browser is deprecated.
+	// Use of jQuery.browser is frowned upon.
 	// It's included for backwards compatibility and plugins,
 	// although they should work to migrate away.
 	browser: {
@@ -628,10 +628,13 @@ jQuery.extend({
 		safari: /safari/.test( userAgent ),
 		opera: /opera/.test( userAgent ),
 		msie: /msie/.test( userAgent ) && !/opera/.test( userAgent ),
-		mozilla: /mozilla/.test( userAgent ) && !/(compatible|webkit)/.test( userAgent )
+		firefox: /mozilla/.test( userAgent ) && !/(compatible|webkit)/.test( userAgent )
 	}
 });
 
+// Deprecated
+jQuery.browser.mozilla = jQuery.browser.firefox;
+
 if ( indexOf ) {
 	jQuery.inArray = function( elem, array ) {
 		return indexOf.call( array, elem );