 Stephen Wolfram’s works in the 1980s contributed to putting the growing community of CA followers on the scientific map. In a series of papers, Wolfram extensively explored one-dimensional CA, providing the first qualitative taxonomy of their behavior and laying the groundwork for further research. A particular transition rule for one-dimensional CA, known as Rule 110, was conjectured to be universal by Wolfram. Some twenty years after the conjecture, Matthew Cook proved that Rule 110 is capable of universal computation (Cook 2004; Wolfram 2002 also contains a sketch of the proof). 