Ripple (XRP) is being used by 100+ BANKs Worldwide.,
Ripple is a real-time gross settlement system (RTGS), currency exchange and remittance network by Ripple. Also called the Ripple Transaction Protocol (RTXP) or Ripple protocol, it is built upon a distributed open source Internet protocol, consensus ledger and native cryptocurrency called XRP (ripples).
Ripple is used on a network blockchain technology to connect banks, payment providers and digital asset exchanges via its own ‘RippleNet’. Ripple aims to provide an incredibly cheap and frictionless experience to facilitate cross border transactions for a multitude of different currencies and assets, making it potentially one of the most scalable digital assets in the world today.
Here is a list of banks that used Ripple https://ripple.com/solutions/