Actually it isn't - when you look at the code and just do some searching you'll find that many, many (!) parts of the code are just copied from other programs/functions - where copyright information then was ripped off and replaced with john's like this:


https://github.com/john-connor/vcash/blob/38ba821efb5e74a7746d81d604af62309e99b343/src/stack.cpp#L29

https://github.com/Packet7/grapevine/blob/cca8b5e8b9f8bf4ef185893071b28a435070e437/src/stack_impl.cpp#L40


It seems like he is using the grapevine implementation for his needs and modified the original code to work with his coind - no doubt that there is some technical skill necessary here, but when you compare the rest of the files (stack.hpp for example) you'll find a lof of similarities which cannot be a coincidence - and everywhere copyright information is removed.

You can do that will almost all files in the repo, just click through the last commits, use some individual function calls for a github / google search and you'll see where the code came / comes from