Ethereum Classic EthereumEthereumEthereum is an open source, public, blockchain-based distributed computing platform and operating system featuring smart contract functionality. It supports a modified version of Nakamoto consensus via transaction-based state transitions.en.wikipedia.org Classic (ETC) is one of two main “Ethereum” coins on the market. It is a hard fork of the original Ethereum blockchain, which is used to develop decentralized applications (dapps) and smart contracts. What Is Ethereum Classic