Glip is fully searchable, real-time group chat; video chat, task management, file sharing app.

Riot allows teams to communicate across a wide range of collaboration apps.

Flock is a communication app for teams. Packed with tons of productivity features, Flock drives efficiency and boosts speed of execution.

Flowdock is a group chat for teams which integrates with GitHub, Jira, Trello.

Hubgets provides chat, voice and video turning team communication.

Tiki Wiki CMS Groupware or simply Tiki, originally known as TikiWiki, is a free and open source Wiki-based content management system and online office suite w…

Bitrix24 is a free (for small businesses) social enterprise platform.

Zulip is a chat and collaborative software.

Gaggle Mail offers group email service.