SubstanceD is a content management system built using the Pyramid web framework. It was created by Chris McDonough and Tres Seaver and provides features like object level security, workflow, and undo capabilities similar to Plone. While SubstanceD has many usable products and allows applications to be easily built on Pyramid, it has a steeper learning curve than Plone and lacks documentation and resources in Japanese. The project also has low development activity currently.