The great thing about Drupal is that you do not need to defend it. The sites made out of Drupal speak for themselves.

From publicly traded corporations such as Nike, Fed-Ex, Yahoo! and AOL to Britney Spears and R.E.M., Drupal is in ever growing demand.

Paul Albert created a presentation to convert Cornell's Medical University Library site to Drupal.

The Case for Drupal-- Why the Open Source CMS is Well-Suited for a Medical Academic Library from Paul Albert on Vimeo.