Open-source Symphony alternatives

Rocket.Chat is a communications platform written in TypeScript for teams and organizations that care about data protection. It supports real-time conversations between colleagues, with partner companies, and with customers or citizens, and its topics place it in the same space as Slack, with WebRTC for calls and meetings.

The product emphasizes control over where and how it runs. Deployment options include self-hosted servers, a managed cloud and fully air-gapped environments, with a scalable architecture and performance monitoring for workspace administration. Security and sovereignty features, including identity management, are a core part of the pitch, and the platform is built to be highly customizable, so organizations can adapt it to their own workflows and integrations.

The repository's license is listed as 'Other' on GitHub, although the topics reference an MIT-licensed community core, so confirm which components fall under which terms before relying on it commercially. It suits government bodies, enterprises and regulated industries that want a Slack-style tool they can host themselves.

Mattermost is an open-core collaboration platform you host yourself, covering team chat, workflow automation, voice calls, screen sharing and AI integrations. This repository is the primary source for core development of the platform. The server is built with Go and React, ships as one Linux binary and depends on PostgreSQL. GitHub lists the license as 'Other'.

Each month, on the 16th, a newly compiled release is published under the MIT license. You can deploy Mattermost on-premises or try it in the cloud. The project highlights use cases such as DevSecOps, incident resolution and IT service desk, and it offers native clients for Android, iOS, Windows, macOS and Linux in addition to the web interface.

Installation options include Docker, Ubuntu, a tar archive, Kubernetes, Helm and an Omnibus package. Developers can build integrations through APIs, webhooks, slash commands, Apps and plugins, and the repository links product and developer documentation, security bulletins and contribution guides. It suits engineering, security and operations teams that want controlled, self-managed team messaging.

Element Web is a client for Matrix, the open protocol for decentralized messaging. It is the web and desktop application formerly known as Vector and Riot, and it lets people join rooms, chat in teams and communities, and collaborate across Matrix servers rather than inside a single vendor's network.

The client is built with TypeScript on top of the Matrix JS SDK. The README defines support tiers for browsers, covering recent versions of Chrome, Firefox, Edge and Safari on desktop, best-effort handling for ESR and extended-stable releases, and community support for mobile web. For phones and tablets the maintainers recommend the native Element X apps for Android and iOS.

It is released under the AGPL-3.0 license and is typically served from your own web host or used through the hosted app from the vendor, Element. Related products such as Element Call and the Enterprise Server Suite are mentioned as part of the wider Element offering. Changes are tracked on GitHub with regular release cycles.

Synapse is a homeserver for the Matrix protocol, an open standard for decentralized, federated chat and real-time communication. It is written in Python using the Twisted framework, with performance-sensitive parts implemented in Rust, and is developed under the element-hq organization.

Running a homeserver lets a person or organization host their own accounts and chat rooms while still communicating with users on other Matrix servers. Synapse is licensed under AGPL-3.0, and its documentation is published at element-hq.github.io/synapse.

This repository contains the source code for the Wire server, the back end of the Wire messaging platform. According to the README, it holds all the libraries and services needed to run Wire. The code is written mainly in Haskell and Rust and is licensed under AGPL-3.0, although the Wire trademark and logos are not licensed for use.

The server is split into services. Nginz is a public API reverse proxy, galley manages conversations and teams, brig handles accounts, gundeck is the push notification hub, cannon delivers WebSocket push notifications, cargohold stores assets such as images and files, proxy covers third-party API integration and spar provides single sign-on. Tools include database migration utilities and a Swagger-based backoffice interface called stern.

The project provides build scripts and Dockerfiles for some platforms, a work-in-progress demo mode that runs in memory and documentation that includes a guide for self-hosting your own Wire server. Federation is described as a long-term roadmap item. Wire itself is a commercial messaging product, and the source is published for transparency and self-hosting.