Ethereumhttps://ethereum.orgSmart-contract L1. Basehttps://base.orgCoinbase's Ethereum L2 — x402's home rail. OpenSeahttps://opensea.ioLargest NFT marketplace. Blurhttps://blur.ioPro-trader NFT market. Magic Edenhttps://magiceden.ioMulti-chain NFT marketplace. Rariblehttps://rarible.comMulti-chain NFT marketplace + protocol. LooksRarehttps://looksrare.orgNFT marketplace with rewards. X2Y2https://x2y2.ioCommunity-run NFT marketplace. Limitless Exchangehttps://limitless.exchangeCrypto prediction market.