Ethereum Classic is the original protocol of Ethereum. As a result of the massive hack on the Ethereum-based DAO, in which around 14% of all ETH in circulation were stolen, a hard fork was proposed to return the stolen funds to their owners. This caused an ideological split revolving around the question of changing previous transactions in the blockchain. Some Ethereum holders rejected the hard fork, and decided to keep using the original protocol, based on the principle that the blockchain is immutable, and cannot be changed.

Vitae is a Proof-of-Stake (PoS) blockchain platform that is a fork of PIVx. It is based on Blackcoin's PoS protocol. The company's marketing materials claim that its focus will be on facilitating social rewards and global prosperity, but they do not provide any specifics about what will distinguish them from other networks. It is powered by the VITAE coin.

Bitcoiin is a cryptocurrency that was created to address some of the issues that have plagued the original Bitcoin ecosystem. It's Proof-of-Work (PoW) consensus mechanism is designed to decrease transactions times and fees, as well as make mining rewards easier to earn.