Web 2.0 has enabled end users to collaborate through their own developed artifacts, moving on from text (e.g., Wikipedia, Blogs) to images (e.g., Flickr) and movies (e.g., YouTube), changing end-user’s role from consumer to producer. But still there is no support for collaboration through interactive end-user developed artifacts, especially for emerging handheld devices, which are the next collaborative platform. Featuring fast always-on networks, Web browsers that are as powerful as their desktop counterparts, and innovative user interfaces, the newest generation of handheld devices can run highly interactive content as Web applications. We have created Ristretto Mobile , a Web-compliant framework for running end-user developed applications on handheld devices. The Webbased Ristretto Mobile includes compiler and runtime components to turn end-user applications into Web applications that can run on compatible handheld devices, including the Apple iPhone and Nokia N800. Our paper rep...