Think of Java, which celebrates its 20th anniversary this week, and your first thoughts most likely go to the language itself. But underneath the language is a piece of technology that has a legacy at least as important and powerful as Java itself: the Java virtual machine, or JVM.
Because the JVM wasn't designed to run any particular language -- Java is only one of many possibilities -- it's become somewhat of a platform unto itself. Languages have been developed for the JVM that owe little or nothing to Java, and the future development of the JVM is turning more to empower the creation of new items that can leverage Java's existing culture of libraries and software or depart from it entirely.