Introducing IBM Semeru Java – regularly updated, community focussed, free and it does everything that Java does.
The IBM Semeru Runtimes are free production-ready binaries built with the OpenJDK class libraries and the Eclipse OpenJ9 JVM. They deliver the power and performance of Java including all the latest up-to-date security and performance fixes. What’s not to love?
IBM Semeru versions and editions
IBM® Semeru Runtimes releases fully implement the Oracle Java™ Platform, Standard Edition (Java SE) application programming interfaces (APIs). The packages are built from the following components:
- OpenJDK class libraries
- Eclipse OpenJ9 Java virtual machine implementation
Release information for the version of each component can be found in the following locations:
- Eclipse OpenJ9: The OpenJ9 release notes summarize any notable changes and limitations in each release.
- OpenJDK class libraries: OpenJDK release information is summarized at the https://foojay.io website.
IBM Semeru Runtimes is available in two editions with different licenses:
- IBM Semeru Runtime Certified Edition has an IBM license and is a Java Platform, Standard Edition compatible implementation.
- IBM Semeru Runtime™ Open Edition has an open source license (GPLv2+Classpath extension).
Refer to the getting started guide on how to use the package name or java -version command to determine the component version and edition.
Download & Install IBM Semeru Runtime
Introducing the no-cost IBM Semeru Runtimes to develop and run Java applications
OK – So what version should I download?
I do not have a specific recommendation for the “best version” of IBM Semeru Java.
IBM Semeru is a distribution of the OpenJDK Java runtime environment, and there are various versions available with different features and support levels.
The “best” version would depend on your specific requirements and use case. Some factors to consider when choosing an IBM Semeru Java version include:
- IBM Semeru currently offers Long‑Term Support (LTS) and non‑LTS versions built from OpenJDK with the Eclipse OpenJ9 JVM. The newest LTS release is Java 25, followed by Java 21 and Java 17, with older non‑LTS versions (24, 23, 22) now out of service.
- Operating system support (e.g., Windows, Linux, macOS)
- Performance and stability
- Security updates and long-term support
- Integration with other IBM products or services
I would suggest reviewing the IBM Semeru Java documentation and release notes to understand the differences between the available versions, and then selecting the one that best fits your needs.
Having said that – as of time of writing I am running SEMERU 25.0.0.0 and it works just perfectly!
JDK vs. JRE – What’s the Real Difference?
JRE (Java Runtime Environment)
Think of the JRE as everything you need to runJava programs, but not to build them. It includes:
- JVM (Java Virtual Machine) executes Java bytecode
- Core libraries the standard Java class libraries
- Runtime components what Java apps need to function
What it does: ✔ Runs existing Java applications ✘ Cannot compile or develop Java code
JDK (Java Development Kit)
The JDK is the full toolbox for Java developers. It includes everything in the JRE, plus tools for building Java programs. It adds:
- javac the Java compiler
- javadoc documentation generator
- debuggers & profilers
- Development tools
What it does: ✔ Compiles Java code ✔ Runs Java applications ✔ Provides tools for development
Quick Comparison Table
| Feature | JRE | JDK |
|---|---|---|
| Run Java programs | ✔ | ✔ |
| Compile Java programs | ✘ | ✔ |
| Includes JVM | ✔ | ✔ |
| Includes development tools | ✘ | ✔ |
| Target users | End‑users | Developers |
Which one should you install?
- If you’re developing Java applications → Install JDK
- If you only need to run Java apps → JRE is enough (though many modern JDKs include the runtime anyway)
If you want to watch a real time download and install – then dive in:
