I saw someone else mentioned his books, but he also was one of the main people behind the CSS 1 test suite (1998) that gave browser manufacturers tests they cou

I saw someone else mentioned his books, but he also was one of the main people behind the CSS 1 test suite (1998) that gave browser manufacturers tests they could target to ensure they were properly rendering to the CSS spec. That went on to eventually evolve into or inspire (can't remember) the CSS acid test that was used for CSS 2 and 3.