The Pyramid authors believe that the MVC pattern just doesn’t really fit the web very well. In a Pyramid application, there is a resource tree, which represents the site structure, and views, which tend to present the data stored in the resource tree and a user-defined “domain model”. However, no facility provided by the framework actually necessarily maps to the concept of a “controller” or “model”. So if you had to give it some acronym, I guess you’d say Pyramid is actually an “RV” framework rather than an “MVC” framework. “MVC”, however, is close enough as a general classification moniker for purposes of comparison with other web frameworks.