Eclipse OpenJ9

https://github.com/eclipse/openj9

Eclipse OpenJ9: A Java Virtual Machine for OpenJDK that’s optimized for small footprint, fast start-up, and high throughput. Builds on Eclipse OMR (https://github.com/eclipse/omr) and combines with the Extensions for OpenJDK for OpenJ9 repo.

What is Eclipse OpenJ9?

Eclipse OpenJ9 is an independent implementation of a Java Virtual Machine. “Independent implementation” means it was built using the Java Virtual Machine specification without using any code from any other Java Virtual Machine.

The OpenJ9 JVM combines with the Java Class libraries from OpenJDK to create a complete JDK tuned for footprint, performance, and reliability that is well suited for cloud deployments.

The original source contribution to OpenJ9 came from the IBM “J9” JVM which has been used in production by thousands of Java applications for the last two decades. In September 2017, IBM completed open sourcing the J9 JVM as “Eclipse OpenJ9” at the Eclipse Foundation. Significant parts of J9 are also open source at the Eclipse OMR project. OpenJ9 has a permissive license (Apache License 2.0 or Eclipse Public License 2.0 with a secondary compatibility license for the OpenJDK project’s GPLv2 license) that is designed to allow OpenJDK to be built with the OpenJ9 JVM. Please see our LICENSE file for more details.

Eclipse OpenJ9 is a source code project that can be built alongside Java class libraries. Cross platform nightly and release binaries and docker containers for OpenJDK with OpenJ9, targeting several JDK levels (like JDK8, JDK10, etc.) are built by the AdoptOpenJDK organization and can be downloaded from the AdoptOpenJDK download site or on DockerHub.

What is the goal of the project?

The long term goal of the Eclipse OpenJ9 project is to foster an open ecosystem of JVM developers that can collaborate and innovate with designers and developers of hardware platforms, operating systems, tools, and frameworks.

The project welcomes collaboration, embraces fresh innovation, and extends an opportunity to influence the development of OpenJ9 for the next generation of Java applications.

The Java community has benefited over its history from having multiple implementations of the JVM specification competing to provide the best runtime for your application. Whether adding compressed references, new Cloud features, AOT (ahead of time compilation), or straight up faster performance and lower memory use, the ecosystem has improved through that competition. Eclipse OpenJ9 aims to continue to spur innovation in the runtimes space.