GMTSAR is an open source (GNU General Public License) InSAR processing system designed for users familiar with the Generic Mapping Tools (GMT). The code is written in C and is highly portable on multiple platforms. In collaboration with Masanobu Shimada from Japanese Aerospace and Exploration Agency (JAXA), Walter Szeliga from Central Washington University, and Eric fielding from Jet Propulsion Laboratory (JPL), we have made a number of improvements to extend the processing to Single Look Complex (SLC) images and increase the number of satellite data types: ERS1/2, Envisat, ALOS-1, Radarsat-2, TerraSAR-X, and COSMO-SkyMed. Support for Sentinel-1 and ALOS-2 will be added by June 2014 assuming the satellites are successfully launched. Finally we are beginning a seamless integration of GMTSAR and GMT5. Source code and example data seta are freely available (no registration or license needed) at http://topex.ucsd.edu/gmtsar . We hope to have a second GMTSAR short course at UNAVCO in the summer of 2014.