Comprehensive development support for ENS (Ethereum Name Service) including name registration, resolution, subdomains, smart contracts, and multichain integration. Use when building applications with ENS for - (1) Domain name registration and management (.eth names), (2) Name resolution (ENS to address, address to ENS), (3) Subdomain creation and management, (4) Avatar and profile records, (5) Smart contract integration with ENS, (6) Multichain resolution (L2s, sidechains), (7) Name Wrapper and permission management (fuses), (8) DNS integration (traditional domains on ENS), (9) Reverse resolution (address to name). Covers library usage (viem, ethers, wagmi), smart contract development (Solidity), ENS protocol architecture (Registry, Resolver, Registrar), and ENS-specific features like wrapped names, CCIP Read, and programmable fuses.