Stackfield is a team communication service from Germany. It offers end-to-end encryption and apps for many desktop and mobile platforms. It also offers audio and video calls directly in the app.

Infomaniak kChat is a unified communication platform, where you can communicate live with your teams and organize projects in a secure and instant way, from the Swiss cloud provider Infomaniak.

OpenTalk is a video conferencing software from Germany. OpenTalk is part of the German Heinlein Gruppe, which also owns the email provider mailbox.org. OpenTalk is open source under the EUPL (European Public License), which is similar to the GPL, but specifically made for the legal framework in the European Union. The tool offers break-out rooms, a voting system and the ability to moderate with multiple people. OpenTalk also offers On-Premise hosting with a Enterprise version and support.

Digital Samba is a video conferencing software from Spain. They offer end-to-end encrypted video conferences, which you can embed into your own services with their low-code API.