In the September 2018 survey we received responses from 1,642,339,233 sites, 222,628,534 unique domains, and 7,785,976 web-facing computers. This reflects gains of 1.1 million unique domains and 28,000 web-facing computers, but a loss of 19 million sites.

Despite the overall increase in number of unique domains this month, all of the major web server vendors experienced losses. The largest gains in September came from lesser known server software — Pepyaka increased by just over 2 million domains, and DPS increased by 893k domains — with both returning to previously seen usage levels after a couple of months of near absence from the survey.

DPS (Data Protection Server), currently the 11th largest server by domains, is used exclusively by GoDaddy to host customer sites that have been created with its Website Builder tool. Last month saw a temporary swing on a single GoDaddy IP Address from DPS to Microsoft, accounting for both last month's Microsoft gains, and this month's loss.

Pepyaka, now the 7th largest server by domains, was last seen in the survey in large volumes in June 2018, being primarily used by Wix web development platform on Amazon AWS infrastructure. Wix has been a long-time user of nginx, and originally moved all user traffic to the commercial NGINX Plus product to future-proof its load balancing needs. The version numbering used by Pepyaka (currently 1.13.10) combined with Wix's previous usage of nginx suggests that it could be based on the March 2018 mainline version of nginx. The loss of Pepyaka from the survey two months ago coincided with Wix moving its customers' sites from Amazon to Cogent Communications. The return of Pepyaka in the September survey coincides with a similar movement of its customers' sites from Cogent Communications to a combination of Wix's own and Google's infrastructure.

In the web-facing computer market, nginx was the only major web server vendor to experience a gain this month, with an increase of over 41,000 (+2%). Unusually both Apache and Microsoft saw a small loss in absolute numbers of web-facing computers this month, dropping 4,900 and 9,500, in addition to their on-going gradual declines in market share. This has resulted in nginx's market share rising to 27.0%.

In the August 2018 survey we received responses from 1,661,467,123 sites, 221,524,704 unique domains, and 7,758,309 web-facing computers. This reflects a loss of 2.21 million sites, but a gain of 952k domains and 23.9k web-facing computers.

While the Apache web server remains the current leading platform in terms of its total number of domains, computers, active sites, and its proportion of the top million busiest sites, it continues to lose market share. All of Apache's figures decreased this month, continuing a slow long-term decline in most metrics. However, Apache continues to experience long-term growth in the absolute number of web-facing computers of approximately 200k per year, but is still losing overall market share. Over the past 12 months, Apache's usage amongst the top million sites has steadily decreased from 39.1% to 34.8%, and the number of domains using its server software has fallen from 83.7 to 75.3 million.

Microsoft's web servers power the largest share of sites, increasing its total from 670 to 675 million this month, representing a 40.65% share. Microsoft servers also experienced the largest growth in terms of domains this month, with an increase of 1.74%, adding just short of a million additional domains to reach a total of 58.4 million. The vast majority of sites using Microsoft web servers run IIS 7.x, which accounts for over 500 million sites. In comparison, IIS 8.x can only be found on around 50 million sites. Despite this, IIS 7.x and 8.x can both be seen on a similar number of computers—562k and 529k respectively. A large portion of IIS 7.x's larger site count can be attributed to link farming, where many sites are often hosted on just a few computers.

Although nginx doesn't yet lead in any metric, it continues to show significant growth. Whereas Apache and Microsoft servers have both lost active sites, nginx has been gaining in numbers, having increased 17.9% over the past year up to 41.9 million—a 22.67% market share. nginx has also increased its total number of web-facing computers by 41.0% over the past 12 months to reach 2.06 million, whereas Apache's and Microsoft's totals have seen comparatively little change of +7.9% and -0.16% respectively. Long-term nginx growth can be seen in all metrics except for the less stable site count. Over the past 12 months, nginx has gained 20.2% more domains, increasing its total to 50.9 million to hold a 23.00% share.

Web giants doing it their way

Apache, Microsoft, and nginx have each achieved their widespread popularity in the server market due to their general availability, but many large companies in the web industry choose to roll out their own solutions. Web giants such as Google, Cloudflare, Alibaba, and Amazon have each turned to creating or modifying their own specialised server implementations to suit their own unique requirements.

Google's custom server software operates on over 23.1 million hostnames and 2.0 million domains. Google open sourced part of its software, the Google Servlet Engine, at the end of 2008, but the software has not received any official public updates in 9 years. Despite this, servers identifying themselves as "GSE" make up over 75% of the active sites hosted by Google itself, with a large portion of those sites constituting Google's Blogger service (blogspot.com). In fact, the Google Servlet Engine was identified on 13.9 million active sites, which is 2.4 million more than all of Microsoft's server software combined, granting it third place in this metric, behind only Apache and nginx.

Taobao, China's largest online marketplace and part of Alibaba Group, developed their own fork of nginx. The fork, known as Tengine, was released back to the community as open source, leading to wider adoption. Tengine now runs on 56.8 million sites, making it the fourth most popular web server by this metric, despite it having only 1.2 million domains.

Cloudflare uses its own custom stack in order to provide content for 18.2 million sites and 6.7 million domains. Cloudflare historically identified their servers as "cloudflare-nginx", however in early 2018 Cloudflare transitioned to identifying their servers as simply "cloudflare" due to the ongoing evolution of their stack. These "cloudflare" servers are now the fourth most commonly identified in terms of total domains.

In the July 2018 survey we received responses from 1,663,673,364 sites, 220,573,018 unique domains, and 7,734,417 web-facing computers. This reflects a gain of 33.4 million sites, 2.80 million domains, and 120k web-facing computers.

In the web-facing computer market, nginx experienced the largest increase (+3.24%), contributing more than half of the overall growth and surpassing two million web-facing computers this month. As a result, it was the only major vendor to experience a gain in market share. nginx also experienced the largest growth in terms of active sites (+7.87%), and top million sites (+0.71%), further increasing its market share in those metrics. Although nginx has slightly fewer domains than last month, it is generally seeing long-term growth in all metrics, and has gained around 10 million domains over each of the past three years.

Apache remains ahead in terms of domains, active sites, web-facing computers, and sites within the top million. However, it continues to see both long and short-term losses in many metrics, with steadily decreasing counts of domains (-0.53%), active sites (-1.15%), and top million sites (-0.98%).

Microsoft's server software leads by total number of sites, of which it had 670 million this month (a 40.28% share), but sits behind Apache and nginx in most other metrics. Microsoft retains second place in total number of domains with a 26.02% market share, and experienced the largest increase this month of nearly 1.4 million domains. This has increased the gap between it and third-placed nginx, which has been steadily gaining on Microsoft, now leaving them 3.24 percentage points apart.

The one metric in which all major vendors continue to see ubiquitous long-term growth is web-facing computers. Since July 2017, the total number of web-facing computers has increased by 1.14 million (+17.3%). This rate of growth is more than double that seen in the year before between July 2016 and July 2017. Although there have been overall increases in the number of computers running Apache and Microsoft webservers, both have continued to lose market share to their faster growing competitor, nginx.

Google's .app TLD takes off

.app is one of many new gTLDs from ICANN's New gTLD Program. ICANN appointed control of the .app TLD to Google after it won the rights in a $25 million auction against twelve other applicants in February 2015. Google hopes that the appropriately named .app TLD will appeal to websites providing applications and application-related services.

The .app TLD only opened for public registration fairly recently on the 8^th May 2018. This month's survey found 185k unique domains running websites under the .app TLD. Whilst many of these domains return parking pages, a number of fully-fledged sites, such as cash.app, have already been launched, with the Netcraft survey detecting over 15k active sites.

One of .app's marketed features is its inclusion within browsers' HTTP Strict Transport Security (HSTS) preload lists. The .app TLD is one of only thirteen where an HSTS preload policy has been applied to a whole TLD. This TLD-wide HSTS policy means that modern browsers will only access .app websites over a secure HTTPS connection, protecting users from trivial man-in-the-middle attacks.