The Common Framework Initiative has already benefited from the participation of ASF+SDF users at CoFI meetings and on the CoFI mailing lists during the design of CASL. It is not expected (nor even desirable) that ASF+SDF users should suddenly switch to being CASL users. They could, however, help substantially with the future development of CASL in connection with the following points:
ASF+SDF could be used for implementing the proposed concrete syntax for CASL, and for checking the parsing of example CASL specifications.
ASF+SDF is especially well-suited for rapid prototyping of the CASL concrete syntax, and for checking not only that example specifications conform to that syntax, but also that they are unambiguous.2
ASF+SDF could be used for automating translation between CASL and other languages, also in connection with the interoperability of tools that were originally developed for use with different languages.
In particular, translation from (a suitable sub-language of) CASL to ASF+SDF would give CASL users access to the rewriting capabilities of ASF+SDF.
The techniques developed for formatting ASF+SDF specifications could be applied to CASL.
Display annotations in CASL are for determining the formatting of function symbols in applications, but they give little direct control of layout. The ASF+SDF experience with pretty-printing documents via an intermediate box language seems attractive.
Some CASL constructs could perhaps be incorporated in the design of future versions of ASF+SDF.
This list is not intended to be exhaustive! The author would like to hear of further ideas for ASF+SDF support for CASL.