PHP is currently the most popular server-side web programming language. It runs 33,53% of the websites on the Internet. Its widespread use for web development can be attributed to the fact it boasts the largest open source community, simplicity and high performance.
Given that PHP is our personal pick, we put together a list of interesting sites that use the same technology. The article outlines some of Alexa’s most popular websites running on PHP and looks into their architecture.
The first on our list is Yahoo, the most trafficked website on the planet with more than 130 million unique users. In 2002 the company switched from C/C++ to PHP. More on how and why they picked it after reviewing all the web technologies is available here.
Wikipedia, the 8th most popular website on the web and the largest online encyclopedia in the world. It’s built on MediaWiki, a platform written in PHP which powers many other popular wikis on the web.
For the skinny on Wikipedia design and architecture, we attached this workbook by Domas Mituzas, who works with Wikipedia and MySQL AB.
Flickr, the web’s leading photo sharing site hosting over 2 billion images. Looking inside Flickr’s general architecture, we found some noteworthy stats.
~ 60,000 lines of PHP code
~ 60,000 lines of templates
~ 70 custom smarty functions/modifiers
~ 25,000 database transactions/second at peak
~ 1,000 pages per second at peak
Friendster, one of the largest social networking sites. It was founded in 2003. A traffic rank of 14 on Alexa and over 50 million users. In 2007 it won the Webware 100 Award for best community site.
Digg, a user driven social content website with over 1.2 million users. They started in late 2004 with a single Linux server running Apache 1.3, PHP 4, and MySQL. 4.0. Today it’s 100 servers hosted in multiple data centers. Further reading available on High Scalability, a nice source of information on the architecture of highly scalable sites.
LiveBid Auctions, a part of amazon.com and the leading provider of live-event auctions on the Internet.
SourceForge.net, the world’s largest development and download repository of Open Source code and applications.
Neopets, a virtual pet website with huge traffic levels. It started in 1999 as a small project by two British college students.
IstockPhoto, a royalty-free stock photo provider and most likely the most popular online photo library with over 2.2 million images as of October 2007.
Far from being complete, this list comprises only some of the most popular websites on the web running on PHP. Hope it has been interesting.