Liliko Chat is a fast and customizable Web chat system. It provides modern features such as desktop notifications, a responsive design, multiple languages and themes, and many more. Integration into existing community systems like phpBB 3 or MyBB is as simple as editing a config file.
twidge is a client for microblogging sites such as Twitter and Identica (identi.ca). It is extremely versatile, can be customized to work the way you want to work, and can be combined with other tools to do just about anything. It can be used interactively from the shell. It is useful directly as-is, and with simple shell aliases can make a highly efficient system to do exactly what you want. It is perfectly capable of being your only client for microblogging. It can also be used in an automated way, via cron(1), or it can even integrate with your email system.
Voisin is a social networking and group collaboration platform. It's a complete Enterprise 2.0 solution that combines all of the technologies you need to implement Enterprise 2.0 best practices in order to help your work force realize the full benefit of social collaboration and knowledge sharing as they work to achieve group goals. It is based on the OpenEdit Framework.