John Edward Warnock (born October 6, 1940) is an American computer scientist and businessman best known for co-founding Adobe Systems Inc., the graphics and publishing software company, with Charles Geschke. Warnock was President of Adobe for his first two years and chairman and CEO for his remaining sixteen years at the company. Although he retired as CEO in 2000, he still co-chaired the board with Geschke. Warnock has pioneered the development of graphics, publishing, Web and electronic document technologies that have revolutionized the field of publishing and visual communications.