Narrow Band Emergency Messaging Software (NBEMS)
Introduction to NBEMS:
Narrow Band Emergency Messaging Software (NBEMS) is an Open Source software suite that allows amateur radio operators to reliably send and receive data using nearly any computer (Windows, Mac, and Linux) and any analog radio without requiring a dedicated digital infrastructure or specialized modem hardware. NBEMS works on both VHF/UHF FM and on HF.
For more information on Narrow Band Messaging Software visit the ARRL NBEMS Webpage