We now have a Django project for our overall ShapeEditor system. We next need to break down our project into applications, following Django's design philosophy of having applications be small and relatively self-contained. Looking back at our design for the overall project, we can see several possible candidates for breaking the functionality into separate applications:

We're going to combine the first three into a single application called shapefiles, which will handle all the shapefile-related logic. We'll then have another application called tms, which implements our tile map server. Finally, we'll define one more application, which we'll called shared, to hold the database models and Python modules that are shared across these applications.

For example, we might have a module named utils.py that is needed by both the shapefile and tms applications. We'll place this into the shared application to make it clear that this code is designed to be shared by various parts of the system.