geoMAD Prime by Paul Murdaugh - After doing some more digging on the GEOS group over at Facebook, I ran across another version of the MAD Magazine (Issue 258, October 1985) program for GEOS on the Commodore 64 that Paul re-wrote in geoAssembler.  This version is 100x faster than the BASIC 2.0 version in the magazine.  There is also a geoBASIC version Paul wrote that you can find here.