ninux - Wireless network community with the goal of creating and expanding a free, open and experimental...
SOGo - SOGo is groupware server with a focus on scalability and open standards.
LibreMesh - An Open Source Sofware for Geek-free Mesh Community Networks.
Baïkal - Cal and CardDAV server
GNUnet - GNUnet is a framework for secure peer-to-peer networking that does not use any centralized or...
Radicale - The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.