90. Explain Drupal Architecture

Drupal is based on less publicized but still widely used architecture Presentation Abstraction Control, or PAC. The menu system acts as the Controller. It accepts input via a single source (HTTP GET and POST), routes requests to the appropriate helper functions, pulls data out of the Abstraction (nodes and, from Drupal 5 onwards, forms), and then pushes it through a filter to get a Presentation of it (the theme system). It even has multiple, parallel PAC agents in the form of blocks that push data out to a common canvas (page.tpl.php).

88. Drupal at a glance

 

Original author(s)	Dries Buytaert
Initial release	January 2001
Stable release	7.27 / 16 April 2014
Development status	Active
Written in	PHP
Operating system	Cross-platform
Size	11.4 MB (uncompressed core)
Available in	Multilingual
Type	Content management framework, Content management system,Community and Blog software
License	GPLv2 or later
Website	drupal.org