Stoyan Stefanov is a Yahoo! web developer, Zend Certified Engineer, book author, and contributor to the international PHP community. He talks regularly about JavaScript, PHP, and other web development topics at conferences and his blog www.phpied.com and also runs a number of other sites, including JSPatterns.com – a site dedicated to exploring JavaScript patterns. Stoyan is the engineering lead of Yahoo's performance optimization tool 'YSlow', as well as other open-source tools and 'PEAR' libraries. <a href="https://www.last.fm/music/Stoyan+Stefanov">Read more on Last.fm</a>. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.