Java Model Railroad Interface
Java Model Railroad Interface is an open source program for model railroad hobbyists, released under GNU General Public License v2. It allows users to control LED lights, horn, or switch the railway of hobbyist open-source or commercials closed-sourced trains.
JMRI is a suite of tools distributed via a single download. The two most popular tools are DecoderPro for programming Digital Command Control decoders, and PanelPro for controlling layouts.