OpenJDK

OpenJDK is an open-source implementation of the Java Platform, which is the foundation for the Java ecosystem. OpenJDK is the result of an effort led by Sun Microsystems (acquired by Oracle Corporation) to make the JDK available under an open-source license. The project was announced in 2006 and the first release was made in October 2007. OpenJDK is widely used in various Linux distributions, such as Ubuntu, Fedora, and Red Hat Enterprise Linux.

History

The OpenJDK project was initiated by Sun Microsystems in 2006, with the goal of making the JDK available under an open-source license. The project was later continued by Oracle Corporation after its acquisition of Sun Microsystems in 2010. In 2017, Oracle Corporation announced that it would be transitioning the OpenJDK project to a GPLv2+CE license, which allows for greater flexibility and compatibility with other open-source projects. The development of OpenJDK involves a community of contributors from various organizations, including Red Hat, Azul Systems, and Canonical Ltd..

Architecture

The OpenJDK architecture is based on the JVM, which is the runtime environment for Java. The JVM is responsible for loading and executing Java bytecode, as well as providing services such as memory management and security. The OpenJDK implementation includes a variety of components, such as the class loader, runtime environment, and development tools. The OpenJDK architecture is designed to be highly modular and extensible, allowing developers to easily add or modify components as needed.

Licensing and distribution

OpenJDK is distributed under the GPLv2 and the Classpath Exception, which allows for the use of OpenJDK in commercial products. The OpenJDK project also provides a GPLv2+CE license option, which is compatible with the GPL. This allows developers to combine OpenJDK with other open-source projects that are licensed under the GPL. OpenJDK is widely used in various Linux distributions, such as Ubuntu, Fedora, and Red Hat Enterprise Linux.

Implementations and variants

There are several implementations and variants of OpenJDK, including IcedTea, OpenJDK 6, and OpenJDK 8. IcedTea is a build and runtime environment for OpenJDK that is designed to be highly customizable and extensible. OpenJDK 6 and OpenJDK 8 are specific versions of the OpenJDK implementation that provide support for different versions of the Java Platform. Other variants of OpenJDK include Azul Systems' Zulu and Red Hat's Red Hat OpenJDK.

Development and community

The OpenJDK project has a large and active community of developers and contributors. The project is hosted on the OpenJDK website, which provides access to source code, documentation, and other resources. The OpenJDK community includes developers from various organizations, including Red Hat, Azul Systems, and Canonical Ltd.. The project uses a mercurial repository for version control and has a bug tracking system for reporting and tracking issues.

Relationship with Oracle JDK

OpenJDK is closely related to Oracle JDK, which is a commercial implementation of the Java Platform developed by Oracle Corporation. Oracle JDK is based on the OpenJDK codebase and provides additional features and support. In 2017, Oracle Corporation announced that it would be transitioning the OpenJDK project to a GPLv2+CE license, which allows for greater flexibility and compatibility with other open-source projects. Today, OpenJDK and Oracle JDK are maintained in parallel, with Oracle JDK providing commercial support and OpenJDK providing a community-driven alternative. Category:Java (software platform)