This is a modification of the excellent Software Defined Radio software by John Melton.  The original sources are in an svn repo revision 1999. See:

http://openhpsdr.org/wiki/index.php?title=Ghpsdr3

The changes are in trunk/src/: 

softrock    - added an IF offset of 9khz (ala PSDR-IQ) 
dspserver  - added IF offset of 9khz 
server       - hpsdr protocol with full control of sdr-widget/Mobo 
receiver     - Makefile modified to compile in x86_64, changed local-audio to direct alsa output, changed portaudio to use callback
QtRadio    - no changes yet.  Same as stock QtRadio 

To run the softrock server (defaults to using pulse for IQ input.  So 
use pulse chooser to set the default pulse source to the IQ sound 
card):

cd ~/ghpsdr3-alex/trunk/bin 
./softrock --si570 --iq --samplerate 48000|96000|192000

To run the dspserver: 
cd ~/ghpsdr3-alex/trunk/bin 
./dspserver 

Then you can run QtRadio to connect to the dspserver that is running. 

As an alternative to softrock server, you can use the modified 
"server", which has been customized to connect to the sdr-widget using 
the hpsdr protocol.  You need to setup sdr-widget for the hpsdr 
protocol (with the WidgetControl.py tool), and then run server: 

cd ~/ghpsdr3-alex/trunk/bin 
./server --si570 --receivers 1 --samplerate 48000|96000|192000

After that, you start dspserver (to connect to this server) and 
QtRadio etc.