

Apple makes the source code to all their core utilities available
Apple makes the source code for many open source things they distribute available, but often only long after they have shipped binaries. And many parts of their OS which they developed in-house which could also be called “core utilities” are not open source at all.
Every Linux distro uses CUPS for printing. Apple wrote that and gave it away as free software.
Apple did not write cups.
It was was created by Michael R. Sweet in 1997, and was GPL-licensed and used on Linux distros before Mac OS X existed. Apple didn’t want to be bound by the GPL so they purchased a different license for it in 2002.
Later, in 2007 they bought the source code and hired msweet to continue its development, and at some point the license of the FOSS version was changed to “GNU General Public License (“GPL”) and GNU Library General Public License (“LGPL”), Version 2, with an exception for Apple operating systems.”
fyi: GNU coreutils are licensed GPL, not AGPL.
there is so much other confusion in this thread, i can’t even 🤦