Open source OpenTalk is open source, naturally. Developed by Heinlein, the product combines years of experience and technological finesse to a video conferencing solution that offers auditable code and free community use - in keeping with our philosophy of independence and digital sovereignty. At the end of 2022, they will publish the code of OpenTalk under (presumably) the EUPL or possibly also AGPLv3. Read more or contact them at https://opentalk.eu/en/community Performance OpenTalk supports small-scale operation on root servers and can be easily scaled for the needs of large enterprises, national data centers or ISPs. Thanks to the Docker and Kubernetes technologies, many hundreds of conferences with very large numbers of participants can be run in parallel, securely and with high performance. Architecture OpenTalk is hosted on dedicated servers in Germany and implemented with a secure, high-performance programming language. Its core architecture was designed from scratch and avoids weaknesses that other conference solutions suffer from, offering 100% data sovereignty. For secure communication and data protection - fully GDPR-compliant. Demo at https://opentalk.eu/en/demo Optionally, all subscribers of Mailbox.org PREMIUM or STANDARD price plan simply log in to the web portal to access the OpenTalk video conferencing feature directly. Read more at https://mailbox.org/en/post/hello-opentalk