nginx (pronounced “engine x”) is a lightweight web server and a reverse proxy server
Nginx is a high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server. The project started in 2002 and became public in 2004. Nowadays it powers several high-visibility sites, such as Netflix, Hulu, Pinterest, CloudFlare, Airbnb, WordPress.com, GitHub, SoundCloud, Zynga, Eventbrite, Zappos, Media Temple, Heroku, RightScale, Engine Yard and NetDNA.
Nnginx has been a free open source software since the beginning with its sources licensed under 2-clause BSD-like license.