Lessons learned from real DSL experiments

Over the years, our group, led by Bob Balzer, designed and implemented three domain-specific languages for use in real applications. Each was invented to “showcase” DSL language design and implementation technology that was the focus of our then-current research. Each of these was actually a prototype for what would have taken more time to engineer and polish before putting into practice. Although each effort was essentially successful, none of the languages was ever followed up with the subsequent engineering efforts that we expected or at least hoped for. Herein I elaborate where these language efforts succeeded and where they failed, gleaning lessons for others who take the somewhat risky step of committing to develop a DSL for a particular user community.