A brand name and software invention of Sun Microsystems. There is the Java “platform,” which is all of it. There’s the Java programming language, widely taught by computer science colleges around the world. And, there is the Java Virtual Machine (JVM; see definition). Java enters digital video discussions because it underlies both the European DVB-MHP (Digital Video Broadcast-Multimedia Home Platform) specifications for interactive television, and the U.S. “OCAP,” or OpenCable Applications Platform.

Java started out as a small, Sun project under an internal code name — “Oak” — and wound up an internationally used way to write small, portable applications, often called “applets,” that can run on any software environment.

At the beginning of the “Oak” project, Sun’s designers decided that existing programming languages, like C and C++, were not suitable for consumer electronics and set-top devices. Not only is C and C++ a compiler-based authoring method — meaning that for every new chip, C-based programs must be re-compiled in order to work. The existing languages were also deemed too complex and large.

Despite its ease of use and suitability, relative to other programming languages, Java is still considered a “hungry client,” in terms of its needs for processing power and memory. Still, all Java-based technologies are community-governed, meaning they are at least more “open” than other, more proprietary options.

An unanticipated and undesired stumble of a signal or bit, as it moves from one place to another. A common cause of jitter is transmission delay. For example, the MPEG-2 digital video compression standard imprints timing information into some of its packets. If the time-stamped packets undergo delays en route, picture distortions can occur at the receive end.

A combination of software interpreter (code that reads code) and the Java language (the code itself). JVM is fairly pervasive in handheld consumer devices, such as Palm Pilots and high-end cell phones. On a set-top level, technologies like JVM matter because they theoretically provide a cushion of control when dealing with interactive applications providers.

Example: An interactive program guide that nestles its code inside set-tops, with additional influence over set-top resource management, like how much processing power and memory gets used by other interactive applications.

With a JVM as the “engine” within cable-delivered “OCAP” applications, coupled with the large and growing base of software coders who write in the Java language, suddenly there’s a path toward moving the guide, or any other application, on top of the JVM.