Guy L. Steele Jr. is a computer scientist who co-created the Scheme programming language with gerald-sussman at the mit-ai-lab during the mit-ai-lab-hacker-culture-1971-1984 era. He was also an early contributor to Emacs, the extensible text editor that stallman developed and which became one of the flagship projects of the gnu-project.
Steele's connection to stallman runs through both the MIT AI Lab's collaborative hacker culture and the early Emacs community. The gnu-emacs-first-release and the subsequent gnu-emacs-manual represent Stallman's most enduring piece of software, and Steele was part of the early Emacs development community that preceded the GNU version.
Scheme itself — the language Steele and Sussman created — influenced Emacs Lisp, the extension language stallman built into GNU Emacs. The Lisp tradition at MIT, of which both Steele and Sussman were central practitioners, is part of the technical and cultural context of the mit-ai-lab-hacker-culture-1971-1984 era.
Steele later worked at Sun Microsystems and Oracle and was involved in the design of Java and Common Lisp standardization. His career exemplifies the path from MIT AI Lab hacker culture into mainstream computing that stallman observed and partly opposed, insisting throughout on the four-freedoms as non-negotiable.