Described is a mechanism for enabling an application operating as a web application to transition to a client-side application without impacting a user's interaction with the application. The progressive installation transitions through three states: a start-up state, a demand state, and an install state....http://www.google.com.au/patents/US7395534?utm_source=gb-gplus-sharePatent US7395534 - System and method for progressively installing a software application
