Steven Kelly on DSM

It was a nice start to my New Year to see kind words about us in Peter Bell's blog. You might have had the pleasure of meeting Peter at OOPSLA or Code Generation, but what you may not know is what a "rock star" guru he is in the ColdFusion community. In our terms, ColdFusion is a DSL solution for dynamic web sites -- like Ruby on Rails, but since 1995. Peter is thus well acquainted with the issues of DSL evolution: in ColdFusion, and in his own DSLs around it. And, as anyone who has met him will attest, he's also a truly great guy to be with: rare in someone with that level of technical skill. (And I so wish I'd said this about him earlier, before having to blog about him saying nice things about us!)

Domain Specific Modeling: Key Vendors

"I'd strongly recommend anyone interested in DSM check out MetaEdit+ and openArchitectureWare.

The commercial (but affordable) MetaEdit+ is still for me the reference implementation for DSM tools and has solved problems such as being able to load old models after upgrading the metamodel that most other vendors haven't come to grips with yet. It doesn't work for every use case, but if it works for you it is a very mature offering and the team has a great deal of technical experience. If nothing else, check it out just to know the questions to ask any other vendor you may be considering!

openArchitectureWare is an open source set of tools for developing DSM solutions within Eclipse. It has really matured recently with better tooling for easily generating plug-ins for textual DSLs based on a meta-model and constraints and it also has good tooling for visual modeling. It isn't as polished or seamless as MetaEdit+ but with the team behind it, it is again one of the products you have to consider if you're going to be doing any DSM and if you use Eclipse it's probably a really strong contender."

openArchitectureWare (oAW to its friends) is a set of little languages for manipulating models: model checking (Check), transformation of models to text (Xpand), models to models (Xtend), and text to models (Xtext). It's most commonly used on Eclipse EMF models, but can work on other models too. The fascinating thing for me is the Xpand language. It's remarkably similar to our MERL, even though there is no shared history: neither party knew about the other until much later on.

MERL and Xpand are both true DSLs for the task of turning models into code or other text. That makes them IMHO much easier to use for creating and maintaining your generators, compared with more simplistic templating languages like JET or T4. It also means that once you have learned to use one, switching to the other is largely just changing the keywords and punctuation.