Albert Wiersch is a father to a 5-year-old son and lives near Dallas, Texas. In 1997 he developed an HTML validator with a custom validation engine, and since then (for over 15 years) has been constantly improving it to keep up with the latest HTML and CSS related standards.
Albert's article
Have You Considered Polyglot Markup?
Did you know web documents can be both HTML and XML-based at the same time? This is what's known as polyglot markup.