Built on Go 1.7.4, Caddy is a lightweight web server that supports HTTP/2 out of the box and automatically integrates with any ACME-enabled certificate authority such as Let’s Encrypt. HTTP/2 is enabled by default when the site is served over HTTPS, and administrators using Caddy will never have to deal with expired TLS certificates for their websites, as Caddy handles the process of obtaining and deploying certificates.