Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application. Developed by University of Strasbourg (France), plus many others.
License: Open Source
Jitsi is an open-source video conferencing solution that offers robust features like large group support and end-to-end encryption, making it ideal for secure meetings. In contrast, Tango is a user-friendly messaging and calling app that emphasizes multimedia communication and ease of use, catering more to personal use cases.