Java

   A programming language and development environment created by Sun Microsystems, designed to create distributed executable applications for use with a Web browser containing a Java runtime environment.

   Java technology has been licensed by literallyhundredsofcompanies,includingIBM, Microsoft, Oracle, Hewlett-Packard, and others interested in developing Web-based and platform-independent applications.

   The Java programming language is a portable, object-oriented language, loosely modeled after C++, with some of the more troubling C++ constructs such as pointers removed. This similarity to C and C++ is no accident; it means that the huge population of professional programmers can quickly applytheirpreviousCexperiencetowriting code in Java.

   Java is designed to support networking and networking operations right from the start and begins with the assumption that it can trust no one, implementing several important security mechanisms. Java is architecturally neutral, does not care about the underlying operating system, and is portable because it makes no assumptions about the size of data types and explicitly defines arithmetic behavior. Java is also multithreaded to support different threads of execution and can adapt to a changing environment by loading classes as they are needed, even across a network.

   Rather than writing code targeted at a specific hardware and operating-system platform, Java developers compile their source code into an intermediate form of bytecode that can be processed by any computer system with a Java runtime environment. The Java class loader transfers the bytecode to the Java Virtual Machine (JVM), which interprets the bytecode for that specific platform. Java class libraries, those files that make up the standard application programming interface (API), are also loaded dynamically. The runtime environment then executes the application, which can run within a Web browser or as a stand-alone application.

   See also bytecode; interpreter; Java applet; Java Developer's Kit; Java Virtual Machine; just-in-time compiler; sandbox.