Superchain

The family of L2 chains all built on Optimism's OP Stack and sharing security infrastructure. Includes OP Mainnet, Base, Zora, World Chain, Mode, and many others. Chains commit to using the stack and paying 15% of sequencer fees to the Optimism Collective; in return they get interoperability via cross-domain messaging and shared upgrades. Comparable concepts: zkSync's Hyperchains (ZK Stack), Polygon's AggLayer, Arbitrum Orbit.