Basically, a Geo-related app should have four modules

1. a business module deals with all the logic.
2. GeoDjango can provide data mapping functions like geoIP, distance calculation, zip code searching etc.
3. OpenStreetMap displays the map.
4. OpenLayer: a javascript library provides zoom, pan, scroll functions on the web page. It’s an implementation of ‘Slippy Map’. a simple demo, check the ‘Related’ section for further information.

Glossary

• Slippy Map is a term of the ‘main openstreetmap.org map display’. It’s an Ajax javascript component loading map tiles from OSM.