Today the Free Software community celebrates the 30th birthday of GRASS GIS! GRASS (Geographic Resources Analysis Support System) is a free and open source Geographic Information System (GIS) software suite used for geospatial data management and analysis, image processing, graphics and map production, spatial modeling, and 3D visualization.
30 years old in software terms is quite old. No Windows, no Mac OS, no Linux. I was probably rolling around with a hybrid Apple ][ and 8-bit Atari combination back then. Good stuff for sure. Heck ARC/INFO (as it was called back then) was probably still running on PRIMOS. Today though GRASS GIS is fairly easy to use. Just hook it up to QGIS and use that GUI to access the GRASS backend. There is an extensive history of GRASS GIS that I encourage everyone to read. I first ran into GRASS back when the project was housed at Baylor University (heck it was over 10 years old back then).
30 years of GRASS, makes you want to sit back and enjoy. Toke, toke it up, man!