why choose Drupal

The magazine I'm web editor for is planning on rebuilding the web site. Main candidate has been Drupal, but yesterday DotNetNuke was suggested as an alternative. (DNN was said to have all/many of the features we were looking for right out of the box.)

I've been trying to find useful comparisons between DNN and Drupal, but so far only with modest success. (For example, opensourcecms.com doesn't have DNN, and cmsmatrix.org mainly lists a number of labels which are difficult to understand and not always relevant.)