There are several open-source chat servers that support encrypted chat and calling. Some popular options include:
Matrix is an open-source, decentralized communication platform that supports end-to-end encrypted chat and voice/video calls. It was created in 2014 by a company called Matrix.org and is now maintained by the Matrix.org Foundation.
One of the key features of Matrix is its decentralized architecture, which allows users to communicate with each other regardless of which server they are connected to. This means that users can communicate with each other using a single account and address, even if they are on different servers.
Matrix also supports a wide range of clients, including web, mobile, and desktop apps, as well as a variety of programming languages and platforms. This makes it easy for developers to integrate Matrix into their own apps and services.
Another important feature of Matrix is its support for end-to-end encryption. This means that all communication between users is encrypted, and only the intended recipients can read it. This helps to keep conversations private and secure, even when they are sent over the internet.
Matrix is also highly extensible and can be integrated with other services and platforms. For example, it can be integrated with other messaging platforms like Slack, Telegram, or WhatsApp, as well as with other types of services like calendars, to-do lists, and more.
Rocket.Chat is an open-source, self-hosted chat server that supports encrypted messaging and audio/video calls. It was first released in 2015 and has since grown in popularity as an alternative to proprietary messaging platforms like Slack and Microsoft Teams.
One of the key features of Rocket.Chat is its ability to be self-hosted, which means that users can install and run the chat server on their own servers or cloud providers. This allows for greater control over data privacy and security, as well as the ability to customize and extend the platform to suit specific needs.
Rocket.Chat also supports a wide range of clients, including web, mobile, and desktop apps, as well as a variety of programming languages and platforms. This makes it easy for developers to integrate Rocket.Chat into their own apps and services.
Another important feature of Rocket.Chat is its support for encrypted messaging and audio/video calls. This means that all communication between users is encrypted, and only the intended recipients can read it. This helps to keep conversations private and secure, even when they are sent over the internet.
Rocket.Chat also offers a range of additional features and capabilities, such as: -support for various file types and multimedia
integration with other platforms and services such as Google Drive, GitHub, and more
customizable roles and permissions
real-time translation
live streaming
screen sharing
Jitsi Meet is an open-source, web-based video conferencing platform that enables users to conduct online meetings, webinars, and video chats. It was first released in 2011 and has since grown in popularity as a free, secure, and easy-to-use alternative to proprietary video conferencing platforms like Zoom and Skype.
One of the key features of Jitsi Meet is its open-source nature, which means that the platform's code is available for anyone to view and modify. This allows for greater transparency and security, as well as the ability to customize and extend the platform to suit specific needs.
Jitsi Meet supports a wide range of browsers and devices, including desktop and mobile devices, which makes it easy for users to join and participate in meetings from anywhere. It also supports a variety of features such as screen sharing, recording, and real-time translation.
Another important feature of Jitsi Meet is its support for end-to-end encryption, which means that all communication between users is encrypted, and only the intended recipients can read it. This helps to keep conversations private and secure, even when they are sent over the internet.
Jitsi Meet also offers a range of additional features and capabilities, such as:
ability to join meetings without an account
ability to schedule and join recurring meetings
ability to invite guests to meetings
ability to join with a dial-in number
Zulip is an open-source, team chat software that is designed to be both powerful and easy to use. It is a relatively new player in the team chat space, but it has quickly gained popularity among developers, businesses, and open-source communities for its unique features and capabilities.
One of the key features of Zulip is its use of a "streams" system, which is designed to make it easy for users to organize and filter conversations. In Zulip, conversations are organized into "streams," which are similar to channels or threads in other team chat apps. This allows users to quickly find and join conversations that are relevant to them, and to easily filter out conversations that are not.
Another important feature of Zulip is its support for a wide range of integrations and APIs. This makes it easy for users to connect Zulip with other tools and services they use, such as Github, Trello, and Google Drive. Additionally, Zulip's APIs make it easy for developers to build custom integrations and bots to suit specific needs.
Zulip also supports rich-text formatting, which makes it easy for users to add formatting, links, and images to their messages. The client also supports typing indication, read receipts, and message editing, which makes it easy for users to communicate more effectively.
In terms of security, Zulip supports end-to-end encryption, which means that all communication between users is encrypted, and only the intended recipients can read it. This helps to keep conversations private and secure, even when they are sent over the internet.
Prosody is an open-source, XMPP (Extensible Messaging and Presence Protocol) server that is designed for use in real-time communication applications. XMPP is a widely-used, open standard for instant messaging and real-time communication, and Prosody is one of the most popular XMPP servers available.
One of the key features of Prosody is its simplicity and ease of use. The server is written in Lua, a lightweight and easy-to-learn programming language, which makes it easy for developers to customize and extend. Additionally, Prosody has a small footprint, which makes it easy to run even on low-spec servers.
Another important feature of Prosody is its high level of security. The server supports the latest XMPP security standards, including end-to-end encryption, and is designed with security in mind. Additionally, Prosody can be configured to use external authentication services, such as LDAP or a database, which makes it easy to integrate with existing user management systems.
Prosody also supports a wide range of modules, which can be used to add additional functionality to the server. These modules include things like support for file transfer, multi-user chat, and more. Additionally, Prosody's APIs make it easy for developers to build custom integrations and bots to suit specific needs.
In terms of performance, Prosody is well-suited for high-traffic, high-availability environments. The server is designed to handle many thousands of simultaneous connections, and can be easily scaled to meet the needs of even the largest deployments.