Open Source Jitsi Alternatives

Signal is a cross-platform encrypted messaging application that has a strong focus on privacy. The application is developed by Signal Messenger LLC and provides users with features like one-to-one and group messages, which can include files, voice notes, images and videos. The software is famous for being used by the whistleblower and privacy advocate Edward Snowden who once said "I use Signal every day, it is the most scalable encryption tool we have".

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Pidgin is a chat application which lets you log into accounts on multiple chat networks simultaneously. Pidgin is developed and released fully free and open-source and provides a plugin architecture that allow anyone to build extensions and connections to new networks and third-party services.

Mumble is a free and open-source voice over IP application primarily designed for gamers. The application features a customizable in game overlay, application skins, conversation recording, and advanced voice activity detection. Anyone can download and use Mumble for free, but if you want your own server, you can rent a managed solution from the company behind Mumble, or host your own.

Jami is a free, open-source. universal distributed communication platform which preserves the user's privacy and freedoms. Jami supports a variety of video input options, including mutliple cameras and image and video files, and the selection of audio inputs and outputs with high quality audio and video codecs.

Matrix.org is an open network for secure, decentralized communication. It gives you a simple HTTP APIs and SDKs (iOS, Android, Web) to create chatrooms, direct chats and chat bots, complete with end-to-end encryption, file transfer, synchronised conversation history, formatted messages, read receipts and more. All conversations on Matrix are replicated over all the servers participating in them, meaning there are no single point of control or failure.

Mattermost is an open-source, self-hostable enterprise team collaboration and messaging application. The software can be deployed to on-premis or to cloud instances. Mattermost is designed for internal use within organizations and businesses in financial services, government, healthcare, remote work, and enterprise DevOps, where teams use Mattermost to power collaboration at every stage of the DevOps lifecycle.

Threema is a messenger application that puts security and privacy first. The application is designed to generate as little user data as possible. The service is fully GDPR-compliant and the company has its own servers hosted in Switzerland. With Threema you can keep in touch with friends, family and co-workers while enjoying privacy and rest assured that you personal data is not commoditized.