From Airesis details page:
Airesis is a free software platform, built by a team of Italian developers and contributors, to enable communities and groups to organize themselves in a productive manner according to the principles of direct democracy and participation. To achieve this goal, the application has been designed as a multifunctional system, which integrates all the tools that can help the development of a community, in particular “social” and deliberative tools.
In order to gain access to Airesis, users first create an account and once logged in, can either look through the open groups or receive invitations to join closed groups. Administrators of groups are able to use permission-based membership in order to manage privileges and permissions of each member. Within the group, the user has access to social tools and deliberative tools. The first, social tools, provide users with blogs to share social messages or updates and event promotion depending on user-designated schedules. The second, deliberative tools, contain a voting system that may be anonymized for electing candidates as well as collecting and deliberating proposals and initiatives.
An introduction video to Airesis (in Italian) can be found here.
Airesis is developed by a team of volunteers and managed by the Tecnologie Democratichie based in Italy.
The source code is available on Github.