On September 14, 2015, our first publicly-trusted certificate went live. We were proud that we had issued a certificate that a significant majority of clients could accept, and had done it using automated software. Of course, in retrospect this was just the first of billions of certificates. Today, Let’s Encrypt is the largest certificate authority in the world in terms of certificates issued, the ACME protocol we helped create and standardize is integrated throughout the server ecosystem, and we’ve become a household name among system administrators. We’re closing in on protecting one billion web sites.