Dojo.storage is a unified API to provide JavaScript applications with storage. It is a generic front-end to be able to provide all JavaScript applications a consistent API for their storage needs, whether this JavaScript is in a browser, a Firefox plugin, an ActiveX control, using Windows Scripting Host, etc. Further, the storage backends can use whatever mechanism is appropriate; dojo.storage automagically detects its environment and available storage options and selects the most appropriate one.
Links:
[1] http://ajaxian.com/archives/dojostorage-offline-access-and-permanent-client-side-storage