The KrystalBox Web Application Framework follows the Model-View-Controller (MVC) design pattern and divides a web application into a set of pages, each of which is constructed from a hierarchical set a components. Pages are instantiated using descriptive XML templates and optional "code-behind" PHP scripts, which contain application specific logic. The framework assumes responsibility for common programming tasks, such as page construction and dispatch, state management, localization/internationalization, and user input validation. It allows developers to dictate an application's behavior through the use of PHP scripts.