Rocket.Chat
Rocket.Chat is a open source team communication service. They offer many guides for self-hosting on different platforms (Docker, Kubernetes, ect.) and clients for Android, iOS, Windows, macOS and Linux.
Other products in category Team communication services
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.
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