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
Hangouts is a user-friendly platform integrated with Google's ecosystem, making it suitable for small to medium-sized meetings. In contrast, Jitsi is a versatile and scalable open-source solution that supports larger meetings without requiring user accounts, ideal for tech-savvy users and organizations looking for customization.