Solid - Solid is a solution for online business meetings.

Flow - Stop managing projects from your inbox.

Meetingbird - Powerful meeting scheduling and notes — right in your calendar

Rocket.Chat - Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.

Mobilimeet - Mobilimeet is a smart collaboration app that makes meeting participants engaged and productive, in every meeting.

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.