>I' m looking for stuff and advice about GIS (Geographic Information System).
>Google can give me stuff, so I' m asking for advice (but stuff too) about integrating GIS with VFP.
>Mainly, I' ve the need of extracting information from Esri-shapefiles from two different files and be able to determine the common area (if exists) between the two polygons: one belonging to the first shapefile and one (polygon) to the second, which may or not (or partially) cover the first one.

Have you looked at ESRI's Map Objects, or Map Objects Lite control?