Jisse Reitsma - living in Hilversum, The Netherlands - is the co-founder of Yireo. As lead developer of Yireo he actively develops and supports the numerous Yireo extensions for Joomla! and Magento. A lot of the Joomla! extensions that Jisse created involve plugin development of some kind: Stand alone plugins, or more complex components that are extended using plugins. It is in this area, where Jisse picked up a lot of knowledge and best practices, which finally resulted in the book Programming Joomla! Plugins.