John Warnock's "linguistic motherboard" and Owen Densmore's "class.ps" smalltalk-like object oriented PostScript programming system, which NeWS and The NeWS toolkit used.
Owen Densmore's work with Bill Atkinson and John Warnock on the Mac printing system, and his "linguistic motherboard" email and "Swiss Army NeWS: A Programmable Network Facility" white paper:
Meanwhile, more about PostScript:
John Warnock's "linguistic motherboard" and Owen Densmore's "class.ps" smalltalk-like object oriented PostScript programming system, which NeWS and The NeWS toolkit used.
https://news.ycombinator.com/item?id=29295116
Owen Densmore's work with Bill Atkinson and John Warnock on the Mac printing system, and his "linguistic motherboard" email and "Swiss Army NeWS: A Programmable Network Facility" white paper:
https://news.ycombinator.com/item?id=33827923
More history of PostScript, JAM, InterPress, and John Warnock's vision of PostScript as a "Linguistic Motherboard":
https://news.ycombinator.com/item?id=37201231