Plone

Plone is an open source content management system based on the Zope application server, written in python. Its known to be powerful, reliable, secure and easy to use. Plone excels when compared to other content-management systems in standards conformance, access control, internationalization, aggregation, user-generated content, micro-applications, active user groups and value. Plone website editing gives you more of a "wysiwyg" feel than most content management systems.