Links

Blogs

1. Michele's GNSS Blog
2. RTL-SDR.com
3. gnss-sdr.ru

Websites

GNURadio

1. Osmocom GNURadio Blocks 
2. GNURadio Video Tutorial Series
3. GNURadio on the RPi
4. GNURadio Suggested Reading Order
5. The Comprehensive GNU Radio Archive Network

RTL-SDR

1. RTL-SDR Discovery and History
2. RTL-SDR Quick Start Guide

Theory

1. I/Q Data for Dummies
2. I/Q Signals Video
3. GPS Theory and Receiver Design

Hardware

1. Homemade GPS Receiver
2. HackRF
3. HackRF Blue
4. HackRF PortaPack
5. Airspy

Matlab

1. ChameleonChips SDR toolbox for Matlab/Simulink

Dead GNSS-SDR Projects

1. https://github.com/gps-sdr/gps-sdr - last commit 6 years ago, built around GN3S
2. https://github.com/trondd/opengnss - last commit 9 years ago, several easy-to-grok python files, says its "pre-0.1 release" so likely not even working

Software

1. GNURadio
2. GNSS-SDR
3. GNSS-SDRLIB
4. RTKLIB
5. Google Earth
6. gqrx
7. gpredict
8. SDR#