I was the primary maintainer of GNU M4 (alongside GNU Libtool & others) for 20ish years (I’m afraid to actually count in case it’s longer), and lead author of GNU Autoconf, GNU Automake & GNU Libtool from New Riders circa 2001.
I bought the beta of this book because I really enjoyed earlier books in this series, and saw that it includes forth (which I’m learning by writing a forth) and m4.
I’ve tech reviewed books for No Starch Press, and APress in the past, and wondered if you’d like me to tech review the m4 chapters of this book?