Libra is stablecoin/cryptocurrency from the Calibra organization that is pegged to a basket of currencies in an effort to reduce volatility. Libra is meant to be used as a method of payments, initially on Facebook related properties. Libra is blockchain-based.
M10 is not a stablecoin, cryptocurrency, or based on blockchain. Instead, using M10's technology, banks issue digital money that is fully fungible between banks on the network. Central banks (or a proxy) issue digital central bank money (M0) and commercial banks issue digital bank money (M1). Both M0 and M1 money is available on a shared, centralized high-speed ledger.