On Jun 6, 2023, at 6:13 PM, Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
"The only possible way to have 100% compatability is copyright infringement. But,
you can certainly come up with something that is similar enough to do what you need."
That's not always true. Another way to get it is to implement from sufficiently high
quality specifications. The DIX Ethernet spec, and the DECnet specs, are examples where
if you do what they say you will have an interoperable implementation.
Unfortunately that level of quality is not common, but it can and has been done.
paul