C Caddy project (sponsored by ZeroSSL) · Reverse proxies & web servers
In-depth entry Go web server and reverse proxy that obtains and renews TLS certificates automatically and is configured with a short Caddyfile or a JSON API
Apache-2.0 Open source Free Self-hosted Nov 2, 2026LE Internet Security Research Group (ISRG) · DNS & domains
In-depth entry Nonprofit certificate authority that issues free, automatically renewable TLS certificates through the ACME protocol
N F5, Inc. · Reverse proxies & web servers
Event-driven HTTP server, reverse proxy, load balancer and mail proxy, distributed as open source under the 2-clause BSD license with a commercial Plus edition
BSD-2-Clause Open source Free Self-hosted Broken