Zope is a very popular application server developed in Python, and serves as the basis for many applications, both robust and feature-rich. Plone is a CMS (Content Management System) built on top of he Zope platform, and is used in various government agencies and various institutions around the globe. It's also considered one of the safest CMS in the world.
Jetworks optimizes applications and portals built with Plone, also creates new products and offers design services.