Jitsi is a collection of free and open-source multi platform voice, videoconferencing and instant messaging applications for the web platform,Windows, Linux, macOS, iOS and Android.(https://jitsi.org/)

• Open Source and Community Contributed.
• No royalty.
• No user based licensing.
• Dedicated Server for the organization gives 100% privacy and protection
  assurance of communication and content.
• Clients available for Android, Apple, F-Droid, Browser and Desktop at (https://jitsi.org/downloads)

99.99% Uptime Assurance

With Jitsi, you can:

• Video conference with multiple users.
• Screen-share desktop and presentations.
• Invite users to a conference via a simple, custom URL (https://demo.mailstack.in/)
• Trade messages and emojis while you video conference,
  with integrated chat.
• Integrated with moodle, Open-source learning platform.
  (https://moodle.org)