A Linux Journal Article on Docbook. While it is XML, and XML is an OK standard way of marking up documents, the example given in the article is quite verbose, because, well, XML is verbose. I'd like to think that LaTeX is much better on that regard.

Compare the example given in the article with a sample file from the LaTeX-project website. While not straight ports of each other, they both show the sample syntax and Simplest Possible Document of their respective languages.