Metropolis : https://metropolis-694d1.web.app/ Byzantium : https://byzantiium.web.app/
Application need nightfall client to run it. EY : https://github.com/EYBlockchain/nightfall_3
Metropolis-Byzantium is a DeFi & NFT protocol to monetise nfts. In web3, many individuals have nfts, but besides being collectible, they are merely lying in wallets. It is not of much use.
Metropolis is the dedicated NFT marketplace of the protocol. While Byzantium is the actual defi platform.
On Byzantium user can make use of NFTs and take private micro-loan by keeping there NFTs as collateral, borrow instant loan using Polygon NightFall Optimistic Zero-knowledge technology.
Byzantium transactions are totally private; no one can see the value/tokenId, sender and receipient of the transaction. User can login directly with there UNS Domain, for each new user, a nightfall account is created.