Nginx 
Official Website
http://nginx.org/enCategory
Web ServersReverse Proxy
nginx [engine x] is an HTTP and reverse proxy server, a mail proxy server, and a generic TCP/UDP proxy server, originally written by Igor Sysoev. For a long time, it has been running on many heavily loaded Russian sites including Yandex, Mail.Ru, VK, and Rambler. According to Netcraft, nginx served or proxied 25.64% busiest sites in September 2019.