IIS
trend
1,728,662 websites

IIS offers both free and paid options

http://www.iis.net

A flexible & easy-to-manage web server... Internet Information Services (IIS) for Windows® Server is a flexible, secure and manageable Web server for hosting anything on the Web. From media streaming to web applications, IIS's scalable a...

VS

Zend Server
trend
3,643 websites

Zend Server offers both free and paid options

http://www.zend.com/en/products/zend_server

Zend Server, the Professional PHP Distribution with Advanced Value-add Capabilities

Market Share by Top Websites

1 IIS is leading in Top 10K Sites, Top 100K Sites, Top 1M Sites and The Entire Web.

2 In terms of market share, Zend Server is clearly lagging behind, losing to IIS in all segments.

Websites Categories

1 IIS has better usage coverage in more websites categories. Including Science & Education, Computers Electronics & Technology, Law & Government, Finance and 20 other categories.

2 Zend Server hasn't got a lead over IIS in any websites category.

Geography

1 IIS is leading in most countries, including United States, China, United Kingdom, Italy and 162 other countries.

2 Zend Server hasn't got a lead over IIS in any country.