English computer scientist, essayist, entrepreneur, investor, and author. Known for his work on the programming language Lisp, co-founding Viaweb (later Yahoo! Store), and co-founding Y Combinator.

Computer scientist known for pioneering work on object-oriented programming and GUI design. Led the design and development of the first modern windowed computer desktop interface and co-developed the Smalltalk programming language. Received the Turing Award in 2003.