SpatialAnalysis
Spatial Analysis uses cells and their relationships to create data abstractions that can be visualized in 3D as continuous surfaces.
DanaTomlin started it all in 1980 with his work on MapAlgebra?.
Dr. JoeBerry's Magic SIS http://www.innovativegis.com/basis/
And a couple of MapInfo trialwares:
Grid Analyser http://www.terris.sk/
MapCalc? http://www.farmgis.com/products/software/mapcalc/default.asp
Surfer http://www.goldensoftware.com/