TCNOpen
Components for IEC61375 standardised communication
... in use on many thousands of trains in the world in order to allow electronic devices to exchange information while operating aboard the same train.
TCNOpen follows the Open Source scheme, as the software is jointly developed by participating companies, according to their role, so as to achieve cheaper, quicker and better quality results.
Licenses:
TRDP: MPLv2.0 http://www.mozilla.org/MPL/2.0/
TRDPSpy: GPL http://www.gnu.org/licenses/gpl.html