For Lispers: How accurate is this portrait of Lisp? 19 years ago
If you have Lisp, you don't need the plethora of XML mini-languages you need in Java and many other languages. You can just keep everything Lisp, and give up nothing in flexibility and still succintly express ideas in your problem domain.
This is what is often referred to as "Domain Specific Languages". With Lisp, you can create a DSL and its still Lisp.
That is what the article is saying, but much more verbosely. In the article's defense, I think it takes something as long as that for people who don't know Lisp to really understand the point.