But in general, Bitcoin Knots is very similar to Bitcoin Core. There are some minor changes here and there, but it is not something rewritten from scratch, and implemented in a completely different way, than Bitcoin Core. Which means, that many fixes, and code changes, are used by both clients, and they share most of the source code.
I think we will see more such implementations based on the consensus code used in core, through the
libbitcoinkernel library.