nginx

Basic HTTP server features
Other HTTP server features
Mail proxy server features
Architecture and scalability
Tested OS and platforms

nginx [engine x] is an HTTP and reverse proxy server, as well as a mail proxy server, 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 20.41% busiest sites in November 2014. Here are some of the success stories: Netflix, Wordpress.com, FastMail.FM.

The sources and documentation are distributed under the 2-clause BSD-like license.

Commercial support is available from Nginx, Inc.

Basic HTTP server features

Other HTTP server features

Mail proxy server features

Architecture and scalability

Tested OS and platforms