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
Bit Chat focuses on secure, decentralized messaging with a strong emphasis on privacy, making it ideal for users seeking confidentiality. Jitsi, on the other hand, offers robust video conferencing capabilities and is more suitable for larger meetings and collaboration.