The one I remember using in the 80s was called "fep" written by
Kazumasa Utashiro of Software Research Associates. It was probbaly posetd
posted to comp.sources.unix usenet group.
comp.sources.unix - volume16
...
fep/ Front end editor program
fep/part01 v16i061: Front end editor program, Part01/05
fep/part02 v16i062: Front end editor program, Part02/05
fep/part03 v16i063: Front end editor program, Part03/05
fep/part04 v16i064: Front end editor program, Part04/05
fep/part05 v16i065: Front end editor program, Part05/05