Automattic was replacing the web server software that underpins its popular WordPress blogging platform, and things weren't going well.

This was 2008, and the company was intent on moving WordPress to software in line with its open source philosophy. The world's best-known web server, Apache, was the obvious choice, but when engineers started tinkering with the way the software was setup, Apache would crash, especially when WordPress was really busy. "We realized that it wasn't super-stable under production traffic," says Barry Abrahamson, a WordPress "systems wrangler" who helped manage the transition.

So Automattic pulled the plug on its Apache migration and bet the company on a then-unknown open source project called Nginx. Five years later, WordPress still runs on Nginx – pronounced "Engine X" – and so many others have followed suit.

At a time when the world's best-known web servers are losing marketshare, Nginx is growing, fueled by a no-frills philosophy and its knack for handling myriad web connections at the same time. Apache is still the king of all web servers, but use of Nginx has nearly doubled over the past two years, according to internet research outfit Netcraft.

It now runs about 15 percent of all websites, including everyone from startups such as CloudFlare and Parse (bought by Facebook earlier this year) to web giants such as Automattic and Netflix. "We use it for everything," says Automattic's Abrahamson. "We run as much of our software stack as possible on top of Nginx."

>At a time when the world's best-known web servers are losing marketshare, Nginx is growing, fueled by a no-frills philosophy and its knack for handling myriad web connections at the same time

In many ways, it's an unlikely success story, but one that underscores the global power of open source software, software that anyone can use and modify – for free.

Nginx was created as a pet project by a Russian systems administrator named Igor Sysoev. The 42-year-old started work on the project in 2002, and the first public code came out that October. Like many open source project leaders, he was trying to scratch an itch. At the time, he worked for Rambler, a fast-growing Russian internet portal, and he needed a server that could handle more traffic than the open source alternatives.

As he developed Nginx, he was able to test the code on Rambler's web properties. But that wasn't where it first went live. It got picked up first by the MP3 download site Zvuki – that was back in 2003 – and then an Estonian online dating service, and finally, it powered Rambler's own photo-sharing site.

By 2005, there were maybe 100 users, but it was hard for English speakers to figure out how to get up and running. Most of the project's documentation was in Russian and so was the its most active discussion list. But in 2006, Engish speakers started posting to Ngnx's discussion list, even as Russian language speakers in the U.S. and other countries helped the project spread, sharing configuration files on blogs and helping to translate the complex documentation so others could pick it up.

When sites like YouTube and Facebook started taking off, Nginx remained obscure, but it was perfectly positioned for the next generation of internet companies, and by the end of decade, it was roping in companies like Automattic and CloudFlare.

In 2009, CloudFlare was building a company that sold websites protection from cyber attacks and services that sped up their performance, and it needed web server software that would work with modern machines that used multi-core processors – computer chips that behave like many chips. According to CloudFlare CEO Matthew Prince, Nginx worked better on multi-core and multiprocessor systems, and it could connect with many more web clients without overwhelming the computer's memory.

Would they have considered obscure Russian software if they hadn't been able to examine the source code? "Never in a million years," Prince says. "If it hadn't been open-source, we wouldn't have trusted it."

Instead, CloudFlare offered Sysoev a job (he declined) and bet the company on the project. Today, the company serves more than 1 trillion web requests per month using Nginx. "The great thing about tech is great tech rises to the top," says Prince. "If it solves the problem... and if it's open source, you can go in and read the source and, worst-case, you can change it."

>'The great thing about tech is great tech rises to the top' Matthew Prince

Today, Nginx is particularly popular among startups like CloudFlare. According to Netcraft, Nginx accounts for more than 40 percent of the 12 million websites that run on Amazon's cloud computing service, which is a mainstay in the startup world. A lot of this growth has come at the expense of Apache, which, like Microsoft's IIS web server, was created back in the 1990s – back when web servers were powered by much simpler chips and operating systems.

Sysoev was serving a real need. "The problem he was solving was really common. It wasn't really a Russian problem," says Andrew Alexeev, director of business development at Nginx. "Everything started to transition more and more to online services, and that meant a bigger number of users per server and more complex architectures."

After Automattic switched to the platform in 2008, founder Matt Mullenweg sent Sysoev an unsolicited donation of $3,500. "Let me know if I can do anything to help," he wrote. "It is very well done."

That's when Sysoev says he knew the project had hit the big time. "It was the largest donation I ever saw," he remembers.

Two years ago, he quit his job at Rambler, and now – with investors including Michael Dell's MSD Capital – he's chief technology officer at a newly formed company that aims to sell a souped-up version of Nginx to corporate users. Last month, the company introduced their first commercial product: Nginx Plus. After more than a decade of development and 100 million web sites, Sysoev is finally ready to cash in.