River

River builds a stablecoin protocol on an omni-CDP design, meaning collateral deposited on one chain can back stablecoin minted against it elsewhere rather than each chain running its own isolated system.

A CDP is a collateralised debt position: you lock an asset, mint stablecoin against it, and repay to get the asset back, with liquidation if the collateral falls too far. Making that work across chains is harder than it sounds, because the protocol needs a reliable view of collateral it cannot see locally. River runs on twelve chains.