OpenTalk is trade-free in the sense that it can be self-hosted thanks to the open code base and a guide: https://gitlab.opencode.de/opentalk/ot-setup – one block could be deducted as there is an Enterprise Edition that apparently offers more features: “In addition to advanced features, automated deployment, scaling based on containerization, monitoring and direct integration into the corporate infrastructure are offered out of the box.” (https://opentalk.eu/en/on-premise-videoconferencing)