Nginx (pronounced "engine x" EN-jin-EKS, stylized as NGINX or nginx) is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache. The software was created by Russian developer Igor Sysoev and publicly released in 2004. Nginx is free and open-source software, released under the terms of the 2-clause BSD license. A large fraction of web servers use Nginx, often as a load balancer.
A company of the same name was founded in 2011 to provide support and NGINX Plus paid software. In March 2019, the company was acquired by F5 for $670 million.