Wikipedia
Nginx
Nginx (pronounced "engine x") is a web server. It can act as a reverse proxy server for TCP, UDP, HTTP, HTTPS, SMTP, POP3, and IMAP protocols, as well as a load balancer and an HTTP cache.
Created by Igor Sysoev in 2002, Nginx runs on Unix, Linux, BSD variants, OS X, Solaris, AIX, HP-UX, and Windows. Released under the terms of a BSD-like license, Nginx is free and open source software.