Butter - Butter is a newly launched chatting application that focuses more on the privacy of its users.

Zulip - Chat for distributed teams. Zulip combines the immediacy of real-time chat with an email threading model. With Zulip, you can catch up on important conversations while ignoring irrelevant ones.

Zoho Cliq - Team chat that's built for work

Slack - A messaging app for teams who see through the Earth!

Swiff - Real-time video collaboration for creators, teams, friends

Flow - Stop managing projects from your inbox.