Launches ArbOS 20 Atlas with Ethereum Dencun and Slash Fees

ArbOS 20 “Atlas” launched March 14, adding Ethereum Dencun support with EIP-4844, EIP-1153, EIP-5656, and EIP-6780. It reduces Arbitrum fees: L1 surplus fee falls from 32 to 0 gwei, L2 base fee from 0.1 to 0.01 gwei, effective March 18. DAO approved Atlas; Orbit L2 chains can self-upgrade. Offchain Labs and Prysm contributed. Stylus integration promises further savings.