Plone features built-in advanced navigation functionalities that contribute to the scalability of the website. The dynamically-generated navigation system ensures that the website will grow in an organized and coherent fashion, and ensures a quality user experience by preventing broken links from happening. Plone's navigation system also enables the creation of "smart folders" that aggregate content from all over the site using canned queries into one specific area, creating an automated alternate navigation system.

As a fully open source product, with complete access to the source code and no hidden costs, the Plone Content Management System is a safe investment.

Plone is used by:

• eBay
• Atkins
• Nokia
• Lufthansa
• NASA / Jet Propulsion Labs
• Duke University
• University of North Carolina
• Durham Public Schools
• Central Intelligence Agency

And many more...

More information is at: http://plone.org/about/sites and http://www.plone.org