Domain specific languages (DSLs) provide a promising solution to directly represent and implement domain concepts [2]. DSLs are visual or textual languages targeted to particular problem domains, rather than generalpurpose languages that are aimed at any software problems. Various DSLs have been proposed and used for describing, for example, security aspects of network applications (e.g., role-based access control, data encryption and secure network links) [3, 4]. Although many experience reports have demonstrated DSLs can improve software development productivity (e.g., [5]), existing DSLs are supported only by specific tools and frameworks; there are few generic frameworks supporting arbitrary DSLs.