Java is a set of computer software and specifications that provides a software platform for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, sandboxed environments to provide many features of native applications through being embedded in HTML pages. Writing in the Java programming language is the main way to produce code that will be deployed as byte code in a Java virtual machine (JVM); byte code compilers are also available for other languages, including Ada, JavaScript, Kotlin (Google's preferred Android language), Python, and Ruby. In addition, several languages have been designed to run natively on the JVM, including Clojure, Groovy, and Scala. Java syntax borrows heavily from C and C++, but object-oriented features are modeled after Smalltalk and Objective-C. Java eschews certain low-level constructs such as pointers and has a very simple memory model where objects are allocated on the heap (while some implementations e.g. all currently supported by Oracle, may use escape analysis optimization to allocate on the stack instead) and all variables of object types are references. Memory management is handled through integrated automatic garbage collection performed by the JVM.
Latest version The latest version is Java 26 released in March 2026. The latest long-term support (LTS) version, Java 25 released in September 2025, it is one of a few LTS versions still supported, down to Java 8 LTS. Oracle extended support for Java 6 ended in December 2018. As an open source platform, Java has many distributors, including Amazon, IBM, Azul Systems, and AdoptOpenJDK. Distributions include Amazon Corretto, Zulu, AdoptOpenJDK, and Liberica. Regarding Oracle, it distributes Java 8, and also makes available e.g. Java 11, both also currently supported LTS versions. Oracle (and others) "highly recommend that you uninstall older versions of Java" than Java 8, because of serious risks due to unresolved security issues. Since Java 9 (as well as versions 10, 12–16, 18–20, and 22–24) are no longer supported, Oracle advises its users to "immediately transition" to a supported version. Oracle released the last free-for-commercial-use public update for the legacy Java 8 LTS in January 2019, and will continue to support Java 8 with public updates for personal use indefinitely.
Platform The Java platform is a suite of programs that facilitate developing and running programs written in the Java programming language. A Java platform includes an execution engine (called a virtual machine), a compiler and a set of libraries; there may also be additional servers and alternative libraries that depend on the requirements. Java platforms have been implemented for a wide variety of hardware and operating systems with a view to enable Java programs to run identically on all of them. The Java platform consists of several programs, each of which provides a portion of its overall capabilities. For example, the Java compiler, which converts Java source code into Java bytecode (an intermediate language for the JVM), is provided as part of the Java Development Kit (JDK). The Java Runtime Environment (JRE), complementing the JVM with a just-in-time (JIT) compiler, converts intermediate bytecode into native machine code on the fly. The Java platform also includes an extensive set of libraries. The essential components in the platform are the Java language compiler, the libraries, and the runtime environment in which Java intermediate bytecode executes according to the rules laid out in the virtual machine specification.
Application domains Different platforms target different classes of device and application domains:
Java Card: A technology that allows small Java-based applications (applets) to be run securely on smart cards and similar small-memory devices. Java ME (Micro Edition): Specifies several different sets of libraries (known as profiles) for devices with limited storage, display, and power capacities. It is often used to develop applications for mobile devices, PDAs, TV set-top boxes, and printers. Java SE (Standard Edition): For general-purpose use on desktop PCs, servers and similar devices. Jakarta EE (Enterprise Edition): Java SE plus various APIs which are useful for multi-tier client–server enterprise applications.
Java SE
Jakarta EE
Java virtual machine
The heart of the Java platform is the "virtual machine" that executes Java bytecode programs. This bytecode is the same no matter what hardware or operating system the program is running under. However, new versions, such as for Java 10 (and earlier), have made small changes, meaning the bytecode is in general only forward compatible. There is a just in time (JIT) compiler within the Java virtual machine (JVM). The JIT compiler translates the Java bytecode into native processor instructions at run-time and caches the native code in memory during execution. The use of bytecode as an intermediate language permits Java programs to run on any platform that has a virtual machine available. The use of a JIT compiler means that Java applications, after a short delay during loading and once they have "warmed up" by being all or mostly JIT-compiled, tend to run about as fast as native programs. Since JRE version 1.2, Sun's JVM implementation has included a just-in-time compiler instead of an interpreter. Although Java programs are cross-platform or platform independent, the code of the Java virtual machines (JVM) that execute these programs is not. Every supported operating platform has its own JVM.
Java Development Kit
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