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 |
| 5.10 | Production version, culmination of Fall 2024 series | Jan 2025 | 11 required 17 recommended |
11 or later |
| 5.12 | Production version, culmination of Spring 2025 series | June 2025 | 11 required 17 recommended |
11 or later |
| (Intended) 5.14 | Production version, culmination of Fall 2025 series | December 2025 | 11 required 21 recommended |
11 or later |
| (Intended) 5.16 | Production version, culmination of Spring 2026 series | June 2026 | 11 required 21 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 11's free support by Oracle ended in September 2023.
Java 17 in 2021 was the LTS release after Java 11. Java 17's free support from Oracle runs through September 2026; after that, there won't be security updates and bug fixes to Java 17.
Starting with the JMRI 5.9.* development series, Java 11 is still supported by JMRI but Java 17 is recommended. We recommend Java 17 to move the user installations forward for eventual future migration, because Java 17 is still getting security updates, and because it's easier to install Java 17 on some OSs.
Java 21 in 2023 was the LTS release after Java 17. We expect that we will have enough confidence in it to start recommending it for use with JMRI 5.13.1 in July 2025. That JMRI release will continue to be compatible with Java 11.
Following Java 21, the next Java LTS release is expected to be Java 25 in September 2025.
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.