If you get nauseous with the smell of XML configuration files, have a look at this refreshing presentation on Domain Specific Languages by Martin Fowler. Nothing groundbreaking in here, yet it's still a very good introduction to the concept and the pros and cons of Language Oriented Programming.
I especially like the part on the learning curve between a complex API in a known (but not always convenient) language vs a simpler API in a custom language... Bull's eye!