A demo showing how to export/download Esri JSON features as a shapefile. All processing happens client side (in the browser).
- The shapefile whitepaper, http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf
- The ArcGIS Geometry format, aka "Esri JSON", http://resources.arcgis.com/en/help/rest/apiref/geometry.html