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This page describes JMRI releases. Briefly, we have three kinds:
If you've never installed a version of this program before, please read the installation guide (on the left) for your computer type and layout hardware. They will show you how to install the things that are needed before the program will run. These additional preliminary steps are one-time only and not necessary when updating. If you've previously installed a working version of the program, you only need to download and install one of the files listed below to update.
See also the page of layout connections.
On March 1, 2021 production release 4.22 was made available.
Release 4.22 is the current "production" release, recommended for first-time users. Please see the release note for additional information.
Test release 4.23.6 was made available on May 26, 2021.
JMRI 4.23.6 is the next release of the current development series, containing the latest and greatest JMRI updates.
The series is working toward the next JMRI production release, probably in early summer 2021.
For more information on the release contents, please see the release note.
These files can be used for either a new installation or updating an existing installation.
We recommend that you verify the downloaded files using the provided sha256 key.
Release 3.10.1 is recommended for JMRI users with computers that can only run Java 1.6. Please see the release note for download and install information.
Production release 3.10.1 was made available on January 11, 2015.
Release 2.14.1 is recommended for JMRI users with computers that can only run Java 1.5. Please see the release note for download and install information.
Production release 2.14.1 was made available on July 15, 2012.
As the program develops, we also produce test releases. You may want to try these, as new features will show up in them first. They are announced in the JMRI users Groups.io group.
The most current test release is JMRI 4.23.6. More information on it, including the links to download a copy, can be found in release note.
For more information on the rough development schedule, please see the JMRI road map (which is only occasionally updated).
Oracle Java Runtime support [more]
The Crandic Automated Traffic System (CATS) is a JMRI-based application by Rodney Black for controlling and operating a model railroad. There's more information on the CATS web site.
CATS 2.34 (Release2037) is compatible with JMRI 3.3.1 thru 3.8. We recommend that you use JMRI 3.8 with it.