"Zwei Was Eine, Initially"
Author: Daniel Weinreb and Mike McMahon? Wikipedia: http://en.wikipedia.org/wiki/ZWEI Source: http://www.heeltoe.com/retro/mit/mit_cadr_lmss.html (As part of a 71MB gzipped tar archive) Family: EmacsFamily Platform: Lisp machine License: Open source
A successor to EINE developed in the early 1980's, and written in [ZetaLisp]. Innovations included programmability in Lisp, and implementing an edit buffer as a doubly-linked list of lines. It was described in Weinrab's thesis: Daniel L. Weinreb, A Real-Time Display-oriented Editor for the LISP Machine, Undergraduate Thesis, MIT EECS Department, January 1979.
It became the preferred editor for Symbolics Lisp Machines.
ZWEI would later become the basis for Zmacs.