Software defined radio receiver
http://www.ecstaticlyrics.com/radio/sdr/natpos/

A Linux based SDR program similar in operation and features to other programs
like GQRX, HDSDR and SDR#. At the moment Natpos only works with RTL-SDR
receivers as it runs via the rtl_tcp interface.
The software demodulates the standard AM/FM/SSB signals and has a frequency
scanner that automatically tunes to the strongest signal