Apple's latest Java update requires you periodically enable the Java plug-in manually. Here is how this works in OS X.

Although Java initially was hailed in the mid-1990s as a way to run client-side applets, the platform instead became known for its server-side capabilities.

“The Java 7u21 release introduces changes to security messages related to running Java applets and applications,” Oracle said in a technical document that explains the changes.

If you do need it, unplug it from the browser unless and until you need it. Java 7 lets users disable Java content in web browsers through the Java control panel applet.

A Java update for Mac OS X 10.6 and 10.7 sets Java applets to not run automatically on all browsers, expanding a feature that was first introduced to Safari in April.

Java’s rapid rise to fame 20 years ago began with a tumbling duke applet running in the HotJava browser, long before Microsoft Internet Explorer, Mozilla Firefox, or Google Chrome were released.