Andreas Gal from Mozilla is implementing the Proxy API that I developed at Google in collaboration with Mark S. Miller. This API enables the creation of dynamic proxies that can intercept a variety of operations applied to Javascript objects. Proxies are currently available in the Firefox 3.7a pre-release and are scheduled to be included in the next Ecmascript standard. I am in the process of writing up a small tutorial to introduce this new feature. A draft specification of the feature for inclusion into ECMAScript harmony is available, and a Google Tech Talk that explains the rationale of our design. Javascript proxies were in part inspired by my earlier work on mirages in AmbientTalk.