Dr. Dobb’s Journal: What Is Drupal?

“Drupal is used to build web sites. It’s a highly modular, open
source web content management framework with an emphasis on
collaboration. It is extensible, standards-compliant, and strives
for clean code and a small footprint. Drupal ships with basic core
functionality, and additional functionality is gained by the
installation of modules. Drupal is designed to be customized, but
customization is done by overriding the core or by adding modules,
not by modifying the code in the core. It also successfully
separates content management from content presentation…”

Complete
Story