I've created a web app to create sample plots from an input shapefile over at elza.pythonanywhere.com which functions mostly as expected.
The problem I am having is that as part of my python script the OGR function "intersects" is used. The function works, but it is not rigorous, meaning it only checks if the envelopes intersect. In order to rigorously check intersection, i.e., using geometries not envelopes, GEOS needs to be enabled. Check out the OGR Intersects help page here to read more about what I mean.
GEOS stands for Geometry Engine Open Source. You can read more about it here. It complements the already installed GDAL/OGR packages by making them more powerful.
I know adding items to the site wide batteries included is a large endeavor, but I would like to pose GEOS as a candidate because without it OGR is much less useful.