The installer should configure the OS to associate *.webapp files with Prism. This means that when you double-click or launch a *.webapp file, Prism is launched and automatically opens the web application.

Current Windows and Mac installs automatically associate *.webapp with Prism.

One interesting side effect is that after this change, you can select a link to a .webapp file in a Web Page and you get it run by Prism - in IE this runs anywhere, but this won't work in Firefox unless the webapp is being issued with an appropriate MIME type on the server: application/x-webapp works (see an example ).