SAPID is build on MVC-paradigm, which is recommended in XML Sapiens specification. A query from a browser comes to index.php script, then direct its steps to the SAPID controller (/mvc/controller/). The query is analyzed than /mvc/model/document_identification.inc.php script identifies current document depending on address string data. Data of a content and template is brought for it. Certain actions performs if it is necessary. Next data of a content and template is gave to XML Sapiens processor (/kernel/ kernel.lib.php). The processor analyzes pointers of XML Sapiens objects. During processing the system calls to related CMS-applications (/usr/extensions/). Completed document comes back to browser.