Skywave Linux is a 64 bit system, built on a base of Ubuntu 16.04 LTS, uses the MATE desktop environment, and draws on the capabilities of Ubuntu: software updating, graphics, system resource management, etc. It is the additional digital signal processing, networking, and signal decoding applications that set Skywave Linux apart from stock Ubuntu Linux. The default username is skywave and there is no password in the default system.

Web forum for the PlutoSDR software defined radio platform.

Information about magnetic loop antennas, amplifiers and more.

A simple SDR console application
SDR client and server for low bandwidth remote operation
Command line receiver for unattended operation
Transmit support (planned for v2 in 2018)
Primarily targeting Linux desktop and SBCs with limited resources
Written in cross-platform C/C++
Easy deployment thanks to minimal external dependencies

Nanosdr is still a work in progress with initial public release expected around the end of 2017

Biggest advantage is that it can do sweeps across large frequency span.

User interface part is written in Processing. Binaries for Windows and Linux are available as well as the source.

Here you can find my software, developed for radio amateur's use, all freeware.

The Universal Radio Hacker is a software for investigating unknown wireless protocols. Features include
   hardware interfaces for common Software Defined Radios
   easy demodulation of signals
   assigning participants to keep overview of your data
   customizable decodings to crack even sophisticated encodings like CC1101 data whitening
   assign labels to reveal the logic of the protocol
   fuzzing component to find security leaks
   modulation support to inject the data back into the system
Dependencies
Required
   Python 3.4+
   numpy / psutil / zmq
   PyQt5
   C++ Compiler

Optional
   librtlsdr (for native RTL-SDR device backend)
   libhackrf (for native HackRF device backend)
   gnuradio / gnuradio-osmosdr (for GNU Radio device backends)

GNSS signal processing functions written in C
       Code generations
       Signal acquisition / tracking
       Decoding navigation messages
       Pseudo-range / carrier phase mesurements
   GUI application (AP) written in C++/CLI
   Visualization of GNSS signal processing in real-time
   Real-time positioning with RTKLIB (http://www.rtklib.com/)
   Observation data can be outputted in RINEX or RTCM format
   Support following signals (tracking and decoding navigation message)
       GPS L1CA
       GLONASS G1
       Galileo E1B
       BeiDou B1I
       QZSS L1CA/SAIF/LEX
       SBAS L1
   Support following front-ends for real-time positioning
       NSL Stereo http://www.nsl.eu.com/primo.html
       SiGe GN3S sampler v2/v3 https://www.sparkfun.com/products/10981
       Nuand BladeRF http://nuand.com/
       RTL-SDR http://sdr.osmocom.org/trac/wiki/rtl-sdr
   Support RF binary file for post processing

Mentioned on https://www.rtl-sdr.com/receiving-gps-with-an-rtl-sdr-dongle-and-gps-antenna/