Optimized to run Java™ applications cost-effectively in the cloud, Eclipse OpenJ9™ is a fast and efficient JVM that delivers power and performance when you need it most.
Optimized for the Cloud, for microservices and monoliths too!
Faster Startup
Faster Ramp-up, when deployed to cloud
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Join us on Slack where you can ask questions and chat directly with our developers. Whether you simply have a question about using OpenJ9, an idea for improvement, or a problem you want to discuss, we'd love to hear from you.
Join OpenJ9 SlackLike all great open source projects, we have a vibrant and busy GitHub repository where you can create issues to explore ideas, request new features, or report any difficulties you are having.
See OpenJ9 IssuesWe welcome contributions to the project in all shapes and forms. If you are interested in JVM development, we'd love to hear your ideas and help you collaborate with us on the code base. There are other ways you can contribute too, such as working on our website and docs. Be a part of the project and share in our success!
Contributor GuideOur regular calls are a great place to find out what is going on in the project. As well as discussing our release plans and development status, we often feature lightning talks by members of the community. For example, technical deep dives or overviews about new features. To see agendas and recordings, look in the Slack #planning channel.
Add to CalendarJuly 2026
We're pleased to announce the availability of Eclipse OpenJ9 v0.60.0.
This release supports OpenJDK 8, 11, 17, 21, 25, and 26. For more information about supported platforms and OpenJDK versions, see Supported environments.
Other updates in this release include the following:
-Xcheck:dump option is enhanced on z/OS systems to validate dataset names that are specified in -Xdump:system options and detects improper VM options. This validation prevents deployment of misconfigured applications and ensures that your diagnostic dumps will be created successfully and will not fail because of invalid dataset names.footprint is added to the -Xtune command-line option. This option is used to optimize Eclipse OpenJ9 VM function by minimizing OpenJ9 VM memory usage.To read more about these and other changes, see the OpenJ9 user documentation.
Performance highlights include the following:
MemorySegment class is used.