Hello everyone, I've been using groff to format my novels since years. Lately I wrote my own version of fmt with some feature added to format troff files (in the head comment of the code I explain its features in more detail.) I decided to share it here, perhaps some of you find it useful:
https://en.roquesor.com/Downloads/fmtroff.c Tested under OpenBSD and Linux. You should be able to compile it under any of these OSs. I take this opportunity to thank developers for maintaining this great software! -- Walter
