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.
oorja - Your Dedicated Meeting Spaces Online — no installations
Kwayet - Team chat & collaboration app, a simple way to Slack
Warmspace - Tech-powered conversations that transform relationships in work and life.
Flow - Stop managing projects from your inbox.
Superpeer Channels - Beautiful livestreams with your subscribers