The Atlantis network upgrade has been successfully activated on Ethereum Classic mainnet at block 8,772,000, bringing Ethereum's Byzantium features to ETC.
Key Improvements
EIP-100: Difficulty Adjustment
Changes the difficulty calculation to account for uncle blocks, providing more stable block times.
EIP-140: REVERT Opcode
Adds the REVERT opcode, allowing contracts to stop execution and return remaining gas while reverting state changes.
EIP-196 & EIP-197: Elliptic Curve Operations
Adds precompiles for elliptic curve operations on the alt_bn128 curve, enabling privacy applications and efficient verification.
EIP-198: Big Integer Modular Exponentiation
Adds a precompile for modular exponentiation, supporting cryptographic operations like RSA verification.
EIP-211: RETURNDATASIZE and RETURNDATACOPY
New opcodes for handling return data from calls, improving smart contract capabilities.
EIP-214: STATICCALL
Adds a new call type that guarantees no state modification, useful for safe view functions.
Significance
Atlantis was a major step in maintaining EVM compatibility between ETC and ETH, ensuring developers could deploy contracts on both networks.