Caddy Web Server

Caddy is a free and open-source, extensible web server that automatically obtains and renews TLS certificates via Let's Encrypt and ZeroSSL. Created by Matt Holt in 2015 (with the company Caddy (Light Code Labs) co-founded with Mohammed Al Sahaf), Caddy is written in Go and designed for simplicity, security, and performance. Caddy is the only major web server with automatic HTTPS by default. Key features: automatic HTTPS: Caddy automatically obtains TLS certificates from Let's Encrypt and ZeroSSL on first launch and renews them before expiry. No manual certificate management is needed. OCSP stapling, HTTP/2, and HTTP/3 (QUIC) are enabled by default. Caddyfile: the human-readable configuration file that makes server configuration simple. A basic site requires just two lines (example.com, respond 'Hello world!'). The Caddyfile supports blocks for site-specific configuration, reverse proxying, and file serving. Reverse proxy: Caddy can act as a reverse proxy with load balancing (round-robin, least_conn, random, IP hash), health checks, and automatic retries. The reverse_proxy directive forwards requests to backend services. Static file serving: Caddy efficiently serves static files with ETag, Last-Modified, and content negotiation. File server with browse mode for directory listings. Dynamic backends: integrate with Consul, etcd, or custom modules for dynamic upstream resolution. API: Caddy exposes a RESTful JSON API for runtime configuration changes without restarting. Plugins: Caddy's modular architecture supports plugins for authentication, caching, compression, security headers (Caddy-Security), WebSockets, FastCGI, and more. Multi-platform: Linux, macOS, Windows, BSD, Docker. Go. Apache-2.0.