Van den Brand, Kuipers, Moonen & Olivier (1997) describe the renovation of the ASF+SDF Meta-Environment and apply an evolutionary, component-based, approach to our own tool suite.
At construction-time, formal specifications (in ASF+SDF) are used to specify the behavior of various components (e.g., syntax-directed editor, program repository, query engine) and component-generators (e.g., parser generator, pretty printer generator, ASF+SDF compiler). When efficiency dictates this, individual components that have been prototyped with ASF+SDF can be replaced by more efficient ones that are, for instance, implemented in C or replaced by an existing tool. Note that DSLs (Section 3.2) are used for describing, syntax, semantics, pretty printing, coordination, and user-interfaces.
At run-time, the TOOLBUS is used to connect components (the ones that have been implemented manually as well as the ones that have been generated) and they can be combined in many ways. In this way, tailored systems can be constructed easily.