Nginx (pronounced "engine X", /ˌɛndʒɪnˈɛks/ EN-jin-EKS) (stylized as NGINX or nginx or NginX) is a web server which can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache. Nginx is free and open-source software, released under the terms of a BSD-like license. A large fraction of web servers use NGINX often as a load balancer.