Thanks! Indeed, I used QGIS for visualization and PostGIS for the processing (with a wee bit of ogr2ogr for some data munging). I really want to do something with OpenLayers to make things a bit more interactive (or at least so I don't have to keep taking lots of screenshots), but that involves either serving up huge GeoJSON blobs or hosting GeoServer. I'll need GeoServer soon anyway so I might as well, but it's more backend work than I have free weekends for at the moment. It's on my list for sure, though.

By the way, hats off to the awesome QGIS, PostGIS, and GDAL (ogr2ogr) projects. I couldn't have done this nearly as easily without their efforts.

These look like maps rendered/exported from GIS software such as ArcGIS.

Those are the default color schemes for QGIS.

I'd put all my fake internet points on it that that was done in QGIS.

Pretty safe bet, since that's what the article says.

- QGIS, for quick sandboxing and ad hoc visualization - PostGIS, for the actual parcel/zone computations - ogr2ogr, for inserting Shapefile data into PostGIS

Didn't rtfa, just scanned over it and looked at the maps.

Unfortunately, I merely found the article. :)