The Drift Protocol is the world's first perpetual swap exchange to use a Dynamic AMM (DAMM). A Dynamic AMM is similar to a virtual AMM (vAMM), but it adds repegging and adjustable k techniques to modify liquidity in a trading pool based on participant demand. As a result, DAMMs are more adaptable than traditional vAMMs and AMMs, resulting in higher capital efficiency and lower slippage.
More details can be found at: https://medium.com/cryptobrosresearch/drift-protocol-a-lightning-fast-scalable-perpetual-futures-dex-f0882dfd7aef