For the first time since it sprang on to the web in 2004, Nginx (pronounced “engine-ex”), the lightweight open source web server that could, has overtaken Microsoft IIS to become the second most used server on the web.

Nginx currently powers some 12.18 percent of the web’s active sites — including big names like Facebook and Wordpress — which means Nginx has just barely squeaked ahead of Microsoft IIS which currently powers 12.14 percent of websites. While Apache is still far ahead of both with over 57 percent of the market, of the top three, only Nginx continues to grow in market share.

These market share numbers come from NetCraft, which has been tracking data like server type and server operating system since 1995. It’s worth noting that Nginx is only ahead in the “active sites” survey which throws out results like parked domains and registar placeholder pages (full details of NetCraft’s methodology can be had here).

Unlike Apache, which, while robust and powerful also uses considerably more resources, Nginx was designed to be fast and lightweight. The server can handle a very large number of simultaneous connections without suffering a performance hit or requiring additional hardware.

The combination of lightweight and fast has made Nginx the darling of the web in recent years with everyone from Facebook to Dropbox relying on it in one form or another. Indeed, another part of Nginx’s success lies in its versatility. The server can be used for everything from a traditional high performance web server to a load balancer, a caching engine, a mail proxy or an HTTP streaming server.

Having recently moved several primarily static websites to Nginx I can also vouch for another of Nginx’s strengths — outstanding documentation.

If you’d like to give Nginx a try head on over to the official site and download a copy today.