1. A method of controlling access by a program fragment to a resource within an aggregated web application runtime environment having a Document Object Model (DOM) structure, said resource associated with a DOM node within the DOM structure, comprising: appending an access attribute to said DOM node, the access attribute associated with a plurality of access rights definitions, each access rights definition defining a set of access rights to said resource for program fragments having an originating domain with a specific access rights status; setting one or more access rights statuses of an originating domain of said program fragment; and granting or denying said program fragment access to said resource based upon the one or more sets of access rights defined for said program fragment according to the access rights statuses of its originating domain.