NAVIPEDIA GNSS tools can be accessed from here.

Hatanaka compression/decompression

RTKLIB is an open source program package for GNSS positioning. Please visit the RTKLIB website for more information.

GPSTk provides a C++ open source library and a suite of applications for GPS processing problems. Please visit the GPSTk website for more information.

GAMIT, GLOBK and TRACK form a comprehensive suite of programs for analyzing GNSS measurements primarily to study crustal deformation. Please check the following link for further information.

GNSS-Inferred Positioning System and Orbit Anlysis Simulation Software. More details can be found here.

GNSS-SDR GNSS Sowfware Design Receiver (source code available from here)