I was visiting your wonderful website and wanted to add a few historical details. I was the founding software architect of GRASS. When I was an engineering student at the University of Illinois I was hired by Bill Goran of the Corps of Engr. Research Laboratory (CERL) to create the first version. It started with a capability to overlay various kinds of raster GIS data and do Boolean combinations on layers of that data. I delivered the first version in 1982. The document describing that work was published later in CERL Technical Report N-154, May 1983.
A short historical note. Around 1981 at the University of Illinois I had lunch with a CERLite named William Dvorak who was also a student. At this lunchtime meeting William said he was graduating and leaving the project, but thought it might be possible to use Boolean algebra to construct and answer questions about maps created from remote sensing data. His insight was both a brilliant and historical one.
Using a yacc parser I constructed the first version of such a program and called the program combinate. I do not know how long this name survived. The user could type in expressions and see them evaluated on multiple layers of maps. The first example I did combined elevation, landsat and watershed data of Fort Hood, in Kileen Texas. That was a pretty big deal back then…
The same idea later appeared a few years later in an image synthesizer built by Ken Perlin that made its way through SIGGRAPH circles.
The GRASS images were some of the first to combine these two kinds of data in the same image. Pat Kane, now of Motorola, implemented a hidden surface algorithm to show elevation and landcover type in 3D simultaneously. I do not think that code was added to the early version of GRASS.
After this, Jim Bozek, now of IBM, added a menu driven user interface and a musician whose name I have forgotten built the first version of a distance-from operator which produced beautiful images.
In 1983 I left Champaign for the University of Utah and recommended as my replacement an engineering friend of mine, Dan Goriesky, who later went to work for the Naval Weapons Center at China Lake.
Later I was the technical director for a project sponsored by National Geographic called the Earth from Space. It was the prototype of the nice image you use for tracking developers.
Starting in 1983 Jim Westervelt added many other capabilities to the system and was an early champion of making GRASS a comprehensive product.
I hope this adds to any history of GRASS that you currently have. I have an extra copy of the CERL report if it is of historical value.
I am glad to see GRASS being distributed under the GNU public license. That is a fitting tribute to its multi-authored legacy.
L. Van Warren MS CS, MS AE