The goal of the GPSTk project is to provide an open source library and suite of applications to the satellite navigation community--to free researchers to focus on research, not lower level coding.  The GPSTk suite consists of a core library, auxiliary libraries, and a set of applications. The GPSTk provides a wide array of functions that solve processing problems associated with GNSS such as processing or using standard formats such as RINEX. The libraries are the basis for the more advanced applications distributed as part of the GPSTk suite.  The GPSTk is sponsored by Space and Geophysics Laboratory, within the Applied Research Laboratories at the University of Texas at Austin (ARL:UT). GPSTk is the by-product of GPS research conducted at ARL:UT since before the first satellite launched in 1978; it is the combined effort of many software engineers and scientists. In 2003, ARL:UT decided to open source much of their basic GNSS processing software as the GPSTk.