Caddy, sometimes clarified as the Caddy web server, is an open source, HTTP/2-enabled web server written in Go. It uses the Go standard library for its HTTP functionality. One of Caddy's most notable features is enabling HTTPS by default. It is the first general-purpose web server to do so without requiring extra configuration. The author, Matt Holt, began developing Caddy in December 2014 and released it in April 2015. In the year following its release, it was downloaded over 20,000 times and received 4,500 stars on GitHub.