There's also a page containing the history, particularly the saga of how we moved forward to Java 1.6 and Java 8 across a series of platform-related changes.
This section describes the history and (notional) plans for JMRI releases in the future.
| Release | Description | Date | JRE | JDK |
|---|---|---|---|---|
| 3.11.* | Development series | 1.6 | 8 | |
| 4.0 | Production version, culmination of 3.11.* series | July 2015 | 8 | 8 |
| 4.2 | Production version, culmination of 4.1.* series | December 2015 | 8 | 8 |
| ... | ... | ... | 8 | 8 |
| 4.22 | Production version, culmination of Fall 2020 series | February 2021 | 8 | 8 |
| 4.24 | Production version, culmination of Spring 2021 series | July 2021 | 8 | 8 |
| 4.26 | Production version, culmination of Fall 2021 series | January 2022 | 8 | 8 |
| 5.0 | Production version, culmination of Spring 2022 series | June 2022 | 11 | 11 |
| 5.2 | Production version, culmination of Fall 2022 series | Jan 2023 | 11 | 11 |
| 5.4 | Production version, culmination of Spring 2023 series | June 2023 | 11 | 11 |
| 5.6 | Production version, culmination of Fall 2023 series | Jan 2024 | 11 | 11 |
| 5.8 | Production version, culmination of Spring 2024 series | June 2024 | 11 | 11 |
| (Intended) 5.10 | Production version, culmination of Fall 2024 series | Jan 2025 | 11 required 17 recommended |
11 or later |
| (Intended) 5.12 | Production version, culmination of Spring 2025 series | June 2025 | 11 required 17 recommended |
11 or later |
The 4.1.* series of test releases in Fall 2015 started the requirement for Java 8. This continued through the following release series. Java 8 continued to be the requirement through the Fall of 2021.
The next long-term-support (LTS) Java release after Java 8 is Java 11 from Fall of 2018. Oracle has aligned their Java and the OpenJDK from that point.
In Spring 2022 the Java version required by JMRI moved forward, making
JMRI 4.27.1 the last JMRI version
running on Java 8.
Newer development releases 4.99.x culminated in the June 2022 production releases
requiring Java 11 and therefore being called JMRI 5.0.
Java 17 is the LTS release after Java 11. Starting with the JMRI 5.9.* development series, Java 11 is still supported but Java 17 is recommended. We recommend Java 17 to move the user installations forward for some future migration, and because it's easier to install Java 17 on some OSs.
Java 21 is the LTS release after Java 17. We do not yet recommend it because of some not-fully-understood compatibility edge cases. It works for some people, but we're not yet certain that it will work for all.
For more information on compatibility, see the compatibility discussion.
More information on Java releases and the operating systems that support them can be found here.
Java installers are now available from multiple sources. Our Java installer page lists a number of them.