Christopher Wolfgang Alexander (born 4 October 1936 in Vienna, Austria) is an architect noted for his theories about design as well as over 200 building projects around the world. Reasoning that users know more about the buildings they need than any architect could, he produced and validated (in collaboration with Sarah Ishikawa and Murray Silverstein) a "pattern language" to empower anyone to design and build at any scale. He moved from England to the United States in 1958, living and teaching in Berkeley, California from 1963. Currently an emeritus professor at the University of California, Berkeley, Alexander lives in Arundel, England.