Ralph Johnson writes...
...the Lisp people have been making DSLs for 20 years. I learned about them about 20 years ago, and the Lisp people had been doing it for 20 years before that, so I think they have been doing it for 40 years. Neverthless, DSLs are only starting to become a hot topic.He also recommends Martin Fowler as a source (written and seen/spoken) for more information and suggests...
These are ideas that need to become ubiquitous.