1. A machine implemented method for making an object owned by a first application that executes in a first isolated execution context accessible to a second application that executes in a second isolated execution context, the method comprising: associating the object with the first isolated execution context; receiving a request to render the object accessible to the second application; and transferring ownership of the object to the second application by changing the isolated execution context that is associated with the object to the second isolated execution context, thereby rendering the object accessible to the second application.