Considering the code and implementation of the blockchain technology, which altcoin do you think has the most differences compared to bitcoin? Please explain these differences and include a link to the "documentation" of the coin if possible. I'll try to research the coin and reply back with my findings.

Things I don't exactly consider as differences: Using different hash function, mining algorithm, asymmetric cryptography (different curve, different signature scheme), and obviously: different supply, block time, block size,...