NGINX

NGINX provides an HTTP server, reverse proxy, content cache, load balancer, and mail and TCP/UDP proxy. It serves static and index files, supports auto‑indexing, gzip compression, range requests, and various filters such as XSLT and SSI. The server can terminate SSL/TLS, including SNI, and offers HTTP/2 and HTTP/3 support with weighted, dependency‑based prioritization. It also includes features for virtual hosting, keep‑alive, pipelining, extensive logging, request rewriting, access control, rate limiting, and A/B testing.

The mail proxy component redirects users to IMAP, POP3, or SMTP back‑ends, authenticating via external HTTP services and supporting common authentication mechanisms, STARTTLS, and SSL. The generic TCP/UDP proxy adds SSL/TLS SNI handling, load balancing, fault tolerance, and address‑based access control for arbitrary TCP or UDP traffic.

Designed for high performance with low resource usage, NGINX is distributed under a 2‑clause BSD‑like license, is self‑hostable, and offers both stable and mainline releases for a wide range of operating systems. Community support is available through forums, and commercial support and training are provided by an external partner.