At the main event of the blockchain week in San Francisco today, Libra co-founder and Vice President of Calibra Products Kevin Weil said that the blockchain is the latest technology in Internet applications for the Internet. Weil once again stressed that Libra is a supplement to the existing legal currency system, not to replace the legal currency system. One of Libra's visions is that Libra allows people to pick up their mobile phones and get borderless financial services in order to get convenient financial services for those who don't get financial services. Libra is an open system with open financial services. Existing payment systems are isolated, and Libra imagines email as a unified open finance.