(For more resources related to this topic, see here.)
Currently Drupal is being used as a CMS in below listed domains
Diversity that is being offered by Drupal is the reason of its growing popularity.
Drupal is written in PHP.PHP is open source server side scripting language and it has changed the technological landscape to great extent.
The Economist, Examiner.com and The White house websites have been developed in Drupal.
A minimum installation requires 15 Megabytes. 60 MB is needed for a website with many contributed modules and themes installed. Keep in mind you need much more for the database, files uploaded by the users, media, backups and other files.
Apache, Nginx, or Microsoft IIS.
Drupal 6: MySQL 4.1 or higher, PostgreSQL 7.1, Drupal 7: MySQL 5.0.15 or higher with PDO, PostgreSQL 8.3 or higher with PDO, SQLite 3.3.7 or higher
Microsoft SQL Server and Oracle are supported by additional modules.
Drupal 6: PHP 4.4.0 or higher (5.2 recommended).
Drupal 7: PHP 5.2.5 or higher (5.3 recommended).
Drupal 8: PHP 5.3.10 or higher.
Multi-site allows you to share a single Drupal installation (including core code, contributed modules, and themes) among several sites
One of the greatest features of Drupal is Multi-site feature. Using this feature a single Drupal installation can be used for various websites.
Multisite feature is helpful in managing code during the code upgradation.Each site will have will have its own content, settings, enabled modules, and enabled theme.
To create a new site using a shared Drupal code base you must complete the following steps:
This article discusses in brief about the Drupal platform and also the requirements for installing it.
Further resources on this subject: