InfoQ has a great (i.e., entertaining, interesting, and pragmatic)
interview with two Domain Specific Language (DSL) developers,
here.
I highly recommend watching it. In that interview, Ruby is used to
define the DSL, but Groovy can also be used for this purpose, for
which all the related resources can be found
here. But, I wanted to really understand what all of
this is about, and even though the sessions on this subject at the
Grails eXchange were helpful, it wasn't until...