What is JMRI? The JMRI project is building tools for model railroad computer control. We want it to be usable to as many people as possible, so we're building it in Java to run anywhere, and …

This will install JMRI to the default location, place shortcuts for DecoderPro and PanelPro on the desktop and create a JMRI Start Menu folder containing shortcuts for typically used JMRI …

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 website.

This page lists hardware and networks that JMRI is known to work with, and provides links to information on how to configure JMRI to work with each particular type.

JMRI needs a "Java Runtime Environment" (JRE) to run but will work fine with the larger "Java Development Kit" (JDK). A JDK is only needed if you want to work on JMRI development, i.e. …

You're not discouraged to dive in, but by taking on JMRI - or any powerful, but complex thing - one step at a time you sort of build a solid foundation that will pay for itself in due time.

The JMRI libraries contain the PanelPro application for creating panels to control or follow your (virtual) model railroad. This page introduces the application, and how to use it.

The JMRI project has compiled a lot of information about decoders from many manufacturers, which we make freely available in several forms. To learn more, see the Decoder Information …

Jun 20, 2025 · If you are currently using JMRI 4.7.3 or earlier on Linux or macOS (Windows doesn't need this), then it's very important that you update to JMRI 4.12 and carrying out the …

The Download page on the main JMRI website provides links to download various JMRI versions, along with links to release notes, etc. Note that there are different downloads for different …