Drupal

Drupal powers some of the web's largest sites with a content type system that goes beyond simple blogs. You define exactly what content is and build custom workflows around it, with granular permission controls and revision history built in. Its taxonomy system lets you organize content in complex, interconnected ways.

This is best suited to publishers, enterprises, and developers who need a deeply customizable platform. The barrier to entry is higher than most alternatives, but for sites that outgrow simple blogging tools, Drupal's flexibility and maturity make it a solid long-term choice.