Deme is an “Open Web CMS/Framework for Social, Semantic Data” that originally started out as a “Free/Open Source Platform for Online Group Deliberation and Dialogue”.
From the preview website:
What basic usage is Deme designed for?
Deme is being developed for groups of people who want to make decisions democratically and to do at least some of their organizational work without having to meet face-to-face. It provides the functionality of message boards and email lists for discussion, integrated with tools for collaborative writing, item-structured and document-centered commentary, straw polling and decision making, and storing and displaying group information. It is intended to be a flexible platform, supporting various styles of group interaction: dialogue and debate, cooperation and management, consensus and voting.
Deme is open-source and its code is available on Github.
Deme is developed by a team of developers headed by Todd Davies, project co-founder and lead investigator.