n.b. since this is marked as "dedicated to the public domain" on the release website, I wonder whether it would be legally permissible to disassemble these versions, produce listings, and use them to produce a FOSS cross platform descendant (keeping in mind the usual issues around trademark law)
... a good point was made in the comments: Borland's Sprint had a very good emulation of the WordPerfect UI, as it also did of WordStar, MS Word, and others.
Sadly for Borland, its amazing emulate-any-other-UI feature came out just around the same time that CUA came along and forced all the DOS apps to harmonize their UIs onto a common standard.
The other killer feature of Sprint was the continuous background saving -- also foxed by DOS getting disk-caching as standard right around the same time.
Saying that, it remains an important app.
AIUI underneath, Sprint was based on an EMACS clone.
Mark of the Unicorn -- still trading, remarkably -- wrote MINCE (MINCE Is Not Complete Emacs) and the separate SCRIBBLE text formatter.
MINCE + Scribble evolved into PerfectWriter. That did quite well in its day; I tried it on a BBC Micro with a Torch Z80 2nd processor.
PerfectWriter evolved into FinalWord, again quite a success in its day. I've read several books written entirely in FinalWord.
Borland bought FinalWord 2 and renamed it Sprint.
ISTM that if the text-formatting part were outsourced to Pandoc or something, or some monstrous Electron thing, the UI and continuous-save parts of Sprint could be re-implemented in GNU Emacs if someone had the will to do it.
ErgoEmacs is a good start on the UI front: forget emulating WordPerfect etc. today. (Maybe provide WordStar keystrokes for the grumpy old gits.) Just put a _good_ CUA UI on Emacs, and give it the ability to handle basic, Markdown-style formatting, and a continuous save and live wordcount feature, and I suspect a lot of people would be interested.
https://gswv.apple2.org.za/a2zine/Sel/WordPerfectPD.html (II/GS WordPerfect homepage) https://groups.google.com/g/comp.sys.apple2/c/LFkDFMYo_LQ (original release announcement) https://www.callapple.org/vintage-apple-computers/apple-iigs... (Y2K patched version)
n.b. since this is marked as "dedicated to the public domain" on the release website, I wonder whether it would be legally permissible to disassemble these versions, produce listings, and use them to produce a FOSS cross platform descendant (keeping in mind the usual issues around trademark law)