GNU's Who, The GNU Team has grown larger in the last few months: Brian Fox and Opus Goldstein have joined Jay Fenlason as the only employees of the Foundation. Most recently, Brian created a stand-alone texinfo formatter and browser..., February, 1988, GNU's Bulletin, vol. 1 no. 4
gnu.org
gnu.org
Gnu Status, by Richard M. Stallman. "5. Documentation system. I now have a truly compatible pair of programs which can convert a file of texinfo format documentation into either a printed manual or an Info file. Documentation files are needed for many utilities.", February 1986, GNU's Bulletin, Volume 1 No. 1
Richard Stallman, January 8, 2012, post on emacs-devel mailing list: "...Info has existed since 1976 or so, in the original Emacs. At that time, Info files were written by hand, and everyone could edit system files on ITS."
linuxjournal.com
What's GNU: Texinfo, Issue 6, Oct 01, 1994, By Arnold Robbins, Linux Journal