Microsoft Teams

Best Self-hosted Alternatives to Microsoft Teams

A curated collection of the 20 best self hosted alternatives to Microsoft Teams.

Enterprise collaboration platform providing persistent chat and channels, audio/video meetings, PSTN calling, screen sharing and file collaboration; integrates with Microsoft 365 apps, calendaring and enterprise identity.

Alternatives List

#1
Rocket.Chat

Rocket.Chat

Rocket.Chat is an open-source communications platform for secure team messaging, channels, DMs, voice/video, integrations, and customer omnichannel support.

Rocket.Chat screenshot

Rocket.Chat is an open-source communications platform designed for secure, mission-critical messaging and collaboration. It provides real-time team chat plus optional omnichannel engagement features for communicating with external users through multiple channels.

Key Features

  • Public and private channels, direct messages, threads, mentions, and reactions
  • Role-based access control and administrative controls for organizations
  • Voice and video calling support (WebRTC)
  • Omnichannel capabilities for customer/citizen support workflows
  • Extensible apps and integrations ecosystem (Marketplace and custom apps)
  • Federation options for connecting multiple Rocket.Chat servers

Use Cases

  • Private Slack-like team chat for companies and regulated environments
  • Secure internal and cross-organization coordination for operations teams
  • Customer support or citizen engagement via an omnichannel inbox

Limitations and Considerations

  • Some advanced features (especially around omnichannel and governance) may depend on enterprise licensing and deployment choices
  • Real-time performance and large deployments require careful sizing and database tuning

Rocket.Chat is a strong fit for organizations that need control over data, flexible deployment options, and a customizable communications stack. It combines modern chat features with extensibility and security-oriented administration for critical operations.

44.7kstars
13.2kforks
#2
Mattermost

Mattermost

Open-source, self-hosted messaging platform for secure team collaboration with real-time chat, audio calls, screen sharing, and integrations.

Mattermost screenshot

Mattermost is an open-source, self-hosted collaboration platform designed for secure team communication and real-time collaboration in high-stakes environments. It supports flexible deployment options, including on-premises or private cloud setups, with enterprise-grade security, governance, and integration capabilities.

Key Features

  • Self-hosted deployment with high availability for mission-critical use
  • Native audio calls and screen sharing within channels
  • Interoperability with external tools (MS Teams, GitLab, Atlassian) and native playbooks
  • Open-source Team Edition licensed under MIT
  • Data control, granular admin and deployment flexibility (air-gapped networks, on-prem/private cloud)
  • Real-time DevSecOps collaboration with integrated playbooks and automation

Use Cases

  • Integrated Security Operations and incident response coordination
  • Real-time DevSecOps collaboration to accelerate software delivery
  • Self-sovereign collaboration and data governance for regulated environments

Limitations and Considerations

  • Team Edition is intended for small teams and is not recommended for government or sensitive workloads

Conclusion: Mattermost offers a secure, self-hosted collaboration platform with deployment flexibility and strong integration capabilities, making it suitable for organizations needing data control and mission-critical workflows.

35.5kstars
8.4kforks
#3
Nextcloud

Nextcloud

Nextcloud is an open-source content collaboration platform providing file sync & share, groupware (calendar, contacts, mail), real-time office editing, chat and video conferencing.

Nextcloud screenshot

Nextcloud is an open-source content collaboration platform that provides file synchronization, sharing, and integrated groupware. It combines file storage, real-time document collaboration, chat/voice/video, calendars and contacts under a single extensible platform.

Key Features

  • File sync & share with web, desktop and mobile clients; WebDAV support for native mounts and third-party clients
  • Real-time collaborative editing with Nextcloud Office (LibreOffice-based online editing)
  • Private communications via Nextcloud Talk: browser and mobile chat, audio/video conferencing, screen sharing and SIP integration
  • Groupware: Calendar (CalDAV), Contacts (CardDAV) and integrated mail features
  • Nextcloud Assistant: integrated/local AI features for summarization, content generation and data-aware queries (platform-integrated)
  • Automation and workflow tools (Flow) plus structured-data app (Nextcloud Tables) and Open Collaboration Services APIs for integrations
  • Storage and backend flexibility: support for object stores (S3-compatible/MinIO/OpenStack Swift), SMB/CIFS, local filesystem and external storage mounts
  • Scalability and performance options: multiple database backends (MySQL/MariaDB/PostgreSQL/SQLite), caching/file-locking with Redis or Memcached, APCu for local cache
  • Extensible apps ecosystem and enterprise add-ons for auditing, access control, compliance and identity integrations

Use Cases

  • Secure enterprise file sync, internal collaboration and compliance-focused deployments for organizations needing data control
  • Education and public-sector deployments requiring granular access control, audit trails and privacy-preserving collaboration
  • Service providers and hosters offering branded/cloud storage and collaboration services built on a customizable platform

Limitations and Considerations

  • Production-scale deployments require careful configuration (database selection, caching, file-locking). SQLite is only suitable for testing or very small installs.
  • Some advanced capabilities (distributed scaling, object-storage primary setups, enterprise-grade support and specific integrations) require additional infrastructure, configuration, or commercial Enterprise services.
  • Performance can degrade if many heavy third-party apps are enabled or if recommended caching (e.g., Redis) is not configured; upgrades and maintenance need planning for large installations.

Nextcloud provides a comprehensive, extensible platform for organizations and individuals who need control over their collaboration stack. It balances a broad feature set with modularity so deployments can be tailored to small setups or large, regulated environments.

34.2kstars
4.7kforks
#4
Jitsi Meet

Jitsi Meet

Self-hostable WebRTC video conferencing with chat, screen sharing, moderation tools, and SDKs for embedding meetings into web and mobile apps.

Jitsi Meet screenshot

Jitsi Meet is an open source video conferencing application built on WebRTC, designed for secure, scalable meetings in the browser and on mobile devices. It can be used as a standalone meeting app or embedded into other products via SDKs.

Key Features

  • Browser-based video meetings with modern WebRTC support
  • Mobile applications for Android and iOS
  • Screen/content sharing for presentations and collaboration
  • In-meeting chat including private conversations
  • Meeting controls such as raise hand, reactions, and polls
  • Virtual backgrounds and common conferencing UX features
  • Integration options via web and native SDKs

Use Cases

  • Team video meetings with screen sharing and chat
  • Hosting community calls, workshops, and webinars
  • Embedding video meetings into an existing web or mobile application

Limitations and Considerations

  • End-to-end encryption is available but may limit some features depending on configuration and client support

Jitsi Meet is a strong choice for organizations that want full control over video conferencing while keeping an easy, browser-first user experience. Its ecosystem and SDK support also make it well-suited for product teams building custom video experiences.

28.7kstars
7.8kforks
#5
Zulip

Zulip

Open-source team chat server with topic-based threading for focused, asynchronous, and real-time communication in distributed teams.

Zulip screenshot

Zulip is an open-source team chat platform designed for both real-time and asynchronous communication. Its distinctive topic-based threading keeps conversations organized, making it easier to follow multiple discussions without losing context.

Key Features

  • Topic-based threading within channels (streams) to keep discussions focused
  • Inbox-style view to prioritize unread conversations
  • Real-time messaging with searchable history
  • Powerful integrations and bots, including webhook-based workflows
  • Granular permissions and administration for organizations and communities
  • Multi-platform clients, including web, desktop, and mobile apps

Use Cases

  • Team communication for engineering, product, and operations groups
  • Open source or community collaboration with many parallel discussions
  • Async-first coordination across time zones while preserving context

Zulip is a strong fit for teams that want the immediacy of chat without sacrificing long-term clarity. Its conversation organization model scales well as the number of channels and active threads grows.

24.7kstars
9.6kforks
#6
Huly

Huly

Huly is an open-source all-in-one platform combining project management, team chat, and collaborative documentation as an alternative to tools like Jira, Linear, Slack, and Notion.

Huly screenshot

Huly is an open-source, all-in-one platform for building and running team workspaces that combine project management, real-time communication, and documentation. It aims to replace a stack of separate tools by unifying issues, collaboration, and knowledge in one system.

Key Features

  • Project and issue tracking for planning and managing work
  • Team chat for real-time communication inside workspaces
  • Collaborative documents with rich text, attachments, and code blocks
  • Real-time co-editing, user mentions, linking documents to issues, and action items
  • Multiple business apps built on the same platform (e.g., CRM, HRM, ATS)
  • API client for programmatic access and building integrations

Use Cases

  • Run a unified workspace for product teams combining issues, chat, and documentation
  • Maintain internal documentation, meeting notes, and roadmaps linked to ongoing work
  • Build custom business applications on top of the Huly Platform framework

Limitations and Considerations

  • Some local/development installations may not support outbound email, which can disable features like password recovery and email notifications

Huly is well-suited for teams that want a single, cohesive system for coordinating work and knowledge. It also provides a platform foundation for extending into broader business workflows such as CRM and HR processes.

24.5kstars
1.7kforks
#7
Element

Element

Element is a Matrix client for secure team messaging and collaboration, offering end-to-end encrypted chats and calls with interoperability across the Matrix network.

Element screenshot

Element is a Matrix-based collaboration and messaging client for web and desktop, designed for interoperable real-time communication across the federated Matrix network. It supports deployments where organizations want control over their communication stack while remaining compatible with other Matrix services.

Key Features

  • Matrix client for rooms, direct messages, and community-style spaces
  • End-to-end encryption for private conversations (Matrix E2EE)
  • Cross-organization interoperability via Matrix federation
  • Audio/video calling capabilities via the Matrix ecosystem
  • Configurable deployment via a static web build and a JSON configuration file
  • Optional desktop app packaging (Electron wrapper)

Use Cases

  • Secure team chat for companies, communities, and public-sector organizations
  • Federated collaboration between multiple organizations using different Matrix servers
  • Self-hosted communication front-end paired with a Matrix homeserver

Limitations and Considerations

  • Requires a compatible Matrix homeserver (such as Synapse) to function
  • Recommended to host the client on a different domain than the homeserver to reduce XSS risk

Element is a widely used Matrix client that emphasizes interoperability, encryption, and deployment flexibility. It is a strong choice for organizations that want modern real-time collaboration without vendor lock-in.

12.7kstars
2.5kforks
#8
SimpleX Chat

SimpleX Chat

Open-source, decentralized messaging network built on a Haskell core with Kotlin Multiplatform and native iOS clients; end-to-end encrypted messaging without user IDs.

SimpleX Chat screenshot

SimpleX Chat is an open-source, privacy-first messaging network designed to operate without any user identifiers. It provides mobile, desktop and terminal clients built on a Haskell core, delivering end-to-end encrypted messaging and group/community features while letting operators run their own servers.

Key Features

  • Messaging without user identifiers: the network is designed to deliver messages and form connections without persistent numeric or textual user IDs.
  • Strong encryption: double-ratchet end-to-end encryption with an additional encryption layer and local database encryption (SQLCipher/SQLite for device storage).
  • Haskell core with native UI bridges: a Haskell-based core library exposed to client UIs via FFI, used by Kotlin Multiplatform (Android/desktop) and native iOS (Swift) apps.
  • Multiple clients and runtimes: Android (Kotlin Multiplatform), iOS (Swift), desktop builds and a terminal/CLI client for Linux/macOS/Windows.
  • Flexible storage backends: SQLite (default for mobile/desktop) and PostgreSQL support for server-side deployments; storage abstraction via a unified store interface.
  • Extensible platform: bots API, SDKs and a directory service for discoverable communities and group moderation tools.
  • Cross-platform build tooling: builds and cross-compilation support using Cabal/Nix and Docker-based build scripts, with prebuilt packages distributed via Play Store, F‑Droid, TestFlight and direct APKs.

Use Cases

  • Private one-to-one messaging and group conversations where participants do not want persistent user identifiers.
  • Community-run groups and moderated communities using the SimpleX directory and community voucher model for server funding.
  • Developers building bots, automations or integrations using the provided bots API and client SDKs.

Limitations and Considerations

  • Platform/build complexity: the Haskell core and cross-compilation workflow make local builds more involved than typical native apps; building from source normally requires Haskell tooling, Nix or Docker images.
  • Mobile support constraints: historically builds targeted newer Android versions and specific CPU architectures; current official builds require modern mobile OS versions (Android 8+ minimum is documented) and some legacy devices may need experimental APKs.

SimpleX Chat is focused on strong privacy guarantees, decentralization and developer extensibility. It is suited for users and communities that require encrypted messaging without traditional identifiers and for developers who want to build bots or host community servers.

10.5kstars
568forks
#9
Screego

Screego

Open-source screen sharing server that runs self-hosted; WebRTC-based with TURN server; Docker or single-binary deployment; browser-based.

Screego screenshot

Screego is an open-source, self-hosted screen sharing tool designed for developers. It delivers high-quality, low-latency screen sharing via WebRTC and runs as a Docker container or a single binary.

Key Features

  • Multi-user screen sharing
  • Secure transfer via WebRTC
  • Low latency and high-resolution streaming
  • Easy deployment via Docker or a single binary
  • Integrated TURN server for NAT traversal
  • GPL-3.0 open-source and actively maintained
  • Browser-based client (no dedicated desktop client)

Use Cases

  • Developer code reviews, pair programming, and technical demos
  • Remote debugging and collaborative troubleshooting
  • Live training and technical presentations

Conclusion

Screego provides a focused, self-hosted alternative for teams needing private, high-quality screen sharing. It is built with Go and TypeScript, and a public demo instance is available for quick evaluation.

10.3kstars
705forks
#10
BigBlueButton

BigBlueButton

BigBlueButton is an open-source virtual classroom and web conferencing platform with real-time audio/video, screen sharing, whiteboards, breakout rooms, polling, and recordings.

BigBlueButton screenshot

BigBlueButton is an open-source virtual classroom and web conferencing system designed primarily for online teaching and learning. It provides real-time collaboration tools for instructors and learners, with features tailored to classroom workflows.

Key Features

  • Real-time audio and webcam video with selectable quality levels
  • Screen sharing for presenters
  • Slide and document presentation with whiteboard annotations
  • Multi-user whiteboards for collaborative activities
  • Public and private chat
  • Breakout rooms for small-group work
  • Polling and in-session feedback tools (such as hand raise)
  • Shared notes for group collaboration
  • Session recording and playback
  • Learning analytics visible to moderators via a Learning Analytics Dashboard

Use Cases

  • Live online classes, lectures, and seminars
  • One-to-one tutoring and office hours
  • Group collaboration sessions using breakout rooms and shared whiteboards

BigBlueButton is a feature-rich, education-focused conferencing platform that goes beyond general-purpose video meetings by emphasizing engagement, facilitation, and classroom-oriented tooling. It is widely used and commonly integrated into learning management systems for delivering virtual instruction at scale.

9kstars
6kforks
#11
Spacebar

Spacebar

Spacebar is an open source, self-hostable Discord-compatible communication platform with text chat, voice, and video, designed to work with existing clients and bots.

Spacebar screenshot

Spacebar is a free and open source communication platform that reimplements Discord’s core user experience as a self-hostable, full-stack system. It aims for compatibility with Discord clients and bots while providing control over configuration, theming, and deployment.

Key Features

  • Discord-compatible API behavior to reuse many existing clients and bots with minimal changes
  • Real-time text chat with gateway-style events
  • Voice and video calling via WebRTC
  • Built-in content delivery (CDN-style) for media and attachments
  • Admin dashboard and configurable limits for communities and deployments
  • Theme system and design customization
  • Plugin/extension approach for adding functionality
  • Decentralization-oriented design goals to reduce single points of failure

Use Cases

  • Host a Discord-like community server for a company, school, or gaming group
  • Run a private collaboration chat with full control over data retention and policies
  • Provide a compatible backend for custom clients, integrations, or bots

Limitations and Considerations

  • Compatibility with all Discord features and third-party clients/bots may vary due to ongoing reimplementation work

Spacebar is a strong option for teams and communities that want a familiar Discord-style experience while retaining control over hosting, customization, and platform behavior. It is especially appealing when Discord API compatibility and real-time communication features are key requirements.

6.6kstars
217forks
#12
Colanode

Colanode

Open-source, local-first Slack and Notion alternative combining team chat, rich docs, databases, and file management with offline-first sync and self-hosting.

Colanode screenshot

Colanode is an open-source, local-first collaboration workspace that combines team chat and a Notion-style knowledge base in a single product. It offers offline-first editing with background sync, aiming to keep teams productive while retaining control over their data.

Key Features

  • Real-time chat for teams, including direct messages and channels
  • Rich text pages for notes, documentation, and wikis
  • Structured databases with custom fields and views (table, kanban, calendar)
  • Local-first workflow: writes and reads happen from a local SQLite database, then sync to the server
  • Real-time collaborative editing using CRDTs (Yjs) for pages and database entries
  • File storage and sharing within workspaces
  • Self-hosted server that can support multiple workspaces and clients (web and desktop)

Use Cases

  • Replace Slack + Notion for small teams with a single integrated workspace
  • Maintain an internal wiki and project knowledge base with real-time collaboration
  • Run an offline-friendly team workspace for unreliable network environments

Limitations and Considerations

  • Concurrent multi-user editing is focused on pages and database records; messages and file operations use simpler non-CRDT models
  • The web app may be in early-preview state depending on deployment choice and version

Colanode is a strong fit for teams that want an integrated chat-and-docs workspace with offline-first behavior. It is designed for self-hosting while still providing a modern collaboration experience across web and desktop clients.

4.6kstars
272forks
#13
Synapse

Synapse

Synapse is a Matrix homeserver implementation for running federated, secure real-time chat and collaboration on your own infrastructure.

Synapse screenshot

Synapse is a Matrix homeserver implementation that powers federated, end-to-end encrypted real-time communication using the open Matrix protocol. It provides the core server-side APIs needed for Matrix clients and for federation with other Matrix servers.

Key Features

  • Matrix Client-Server API for chat, rooms, presence, and device management
  • Server-to-Server federation to communicate with other Matrix homeservers
  • End-to-end encryption support via Matrix encryption primitives and device tracking
  • Moderation and administration capabilities for users, rooms, and server policy
  • Pluggable authentication options (commonly used with SSO/OIDC deployments)
  • Scales from small communities to large deployments with supported production setups

Use Cases

  • Running a private or community Matrix chat server with federation support
  • Operating an enterprise messaging backend for Matrix clients (including Element)
  • Hosting regulated or controlled-communication deployments with central administration

Limitations and Considerations

  • Requires careful operational tuning for larger instances (database, caching, and workers)
  • Feature completeness can depend on Matrix spec evolution and enabled server modules

Synapse is widely used in the Matrix ecosystem and is actively maintained, providing a stable foundation for self-managed, interoperable real-time communications. It is typically deployed alongside a reverse proxy and other Matrix components depending on the desired feature set.

3.7kstars
467forks
#14
Tailchat

Tailchat

Tailchat is an open source team chat and collaboration platform with a strong plugin system, bot integrations, multi-group workspaces, and RBAC permissions.

Tailchat screenshot

Tailchat is an open source “noIM” (not only instant messaging) team collaboration app that combines chat with an extensible platform for integrating tools and workflows. It supports multi-group workspaces, panels for organizing topics, and a plugin-centered approach for customization.

Key Features

  • Real-time messaging with multiple message types (text, links, mentions, images, files) and reactions
  • Workspace and group structure with panels to organize conversations by topic
  • Inbox-style notifications for mentions and plugin events
  • Plugin center for extending the UI and embedding tools (e.g., whiteboards, conferencing, utilities)
  • Bot and open platform integrations via simple URL requests or OpenAPI apps
  • Built-in RBAC permission system with roles and permission points that plugins can extend
  • Optional AI assistant features such as rewriting, simplifying text, and summarizing chat history
  • Multi-platform support with web-based UI and dedicated clients for native capabilities

Use Cases

  • Replacing Slack/Discord-style chat for teams that want deeper customization
  • Building an internal collaboration hub by embedding third-party tools through plugins
  • Adding automation and notifications from external systems using bots and OpenAPI

Limitations and Considerations

  • The third-party developer interfaces and plugin APIs may still evolve and can introduce breaking changes over time

Tailchat fits teams that want a modern chat experience but also need a flexible integration and extension model. Its plugin system and RBAC design make it suitable for both small groups and larger, structured organizations.

3.5kstars
388forks
#15
Converse.js

Converse.js

Converse.js is an open-source, client-side web XMPP/Jabber chat app that can run standalone or be embedded into sites, with group chat and OMEMO encryption.

Converse.js screenshot

Converse.js is a modern, feature-rich XMPP (Jabber) chat client that runs entirely in the web browser. It can be deployed as a full-page web app or embedded into existing websites as an overlay or inline widget.

Key Features

  • Multiple UI modes: full-page app, overlay chat boxes, or embedded components
  • Direct messages and multi-user chat rooms (MUC)
  • OMEMO end-to-end encryption (server support required)
  • Message features such as corrections, retractions, moderation, reactions, and styling
  • HTTP File Upload support for file sharing (server support required)
  • Desktop notifications and presence/status indicators
  • Extensive XMPP protocol support (wide range of XEPs)
  • Plugin-based architecture for customization and extensions
  • Internationalization with many community translations

Use Cases

  • Add an embeddable chat widget to a community or support website backed by an XMPP server
  • Provide a browser-based client for an organization’s existing XMPP/Jabber infrastructure
  • Host secure group chat rooms with moderation features for teams or public communities

Limitations and Considerations

  • Feature availability depends on the connected XMPP server and enabled XEP support (for example, OMEMO, file upload, URL previews)

Converse.js is a strong option for anyone needing a standards-based web chat client with flexible embedding options. Its broad XMPP support and extensibility make it suitable for both simple deployments and deep integrations.

3.2kstars
810forks
#16
Ergo

Ergo

Ergo is a modern IRC server (ircd) written in Go, with integrated account management, history storage, bouncer-like features, and strong IRCv3 support.

Ergo screenshot

Ergo (formerly Oragono) is a modern IRC server daemon written in Go. It combines an IRCd with built-in services functionality to provide accounts, persistent history, and bouncer-like behavior in a single deployable server.

Key Features

  • IRC server daemon (ircd) designed to be simple to set up and operate
  • Integrated account management and channel registration/services-style commands
  • Persistent message history and bouncer-like user experience without separate software
  • Strong IRCv3 support, suitable for modern IRC clients and networks
  • Highly customizable, runtime-reloadable YAML configuration (rehashable config)
  • SASL authentication support for automatic account login from clients

Use Cases

  • Hosting a private or community IRC network with modern IRCv3 features
  • Running an IRC server with built-in accounts and registered channels without extra services
  • Providing persistent history for users across reconnects without an external bouncer

Ergo is a strong choice for running an IRC network that needs modern protocol capabilities while keeping operations straightforward. Its integrated approach reduces the need to deploy separate services components for many common IRC network needs.

3.1kstars
227forks
#17
Jitsi Videobridge

Jitsi Videobridge

An open-source WebRTC SFU that routes media for scalable multiparty video conferencing; supports Colibri XMPP/REST control, DTLS/SRTP, and Prometheus metrics.

Jitsi Videobridge screenshot

Jitsi Videobridge is an open-source WebRTC Selective Forwarding Unit (SFU) that routes media streams between participants to enable scalable multiparty video conferencing. It is a core backend component of the Jitsi Meet stack and is designed for high scalability and low CPU overhead.

Key Features

  • Selective Forwarding Unit (SFU) architecture: forwards participant streams rather than mixing, improving quality and scalability for many-participant conferences.
  • WebRTC-native media support: handles RTP/RTCP streams, common codecs, and NAT traversal (ICE/STUN/TURN) with secure transport via DTLS/SRTP.
  • Control APIs: supports Colibri XMPP control as well as HTTPS/REST control endpoints for orchestration, load balancing, and automation.
  • Observability: exports operational statistics and Prometheus-format metrics (private HTTP /metrics endpoint) plus JSON and XMPP-stat reports for monitoring and autoscaling.
  • Implementation & build: primarily Kotlin and Java codebase, built with Maven and running on the JVM.
  • Deployment options: packaged for Debian/Ubuntu, runnable locally via Maven, and commonly deployed in containerized or multi-node topologies for capacity.

Use Cases

  • Powering large-scale multiparty video conferencing (used by Jitsi Meet) where many participants join without per-stream server mixing.
  • Backend media routing for webinar platforms, remote education, telehealth, and enterprise meeting services requiring scalable, low-latency forwarding.
  • Integrating into custom WebRTC applications that need a flexible SFU with XMPP or REST control and observability hooks.

Limitations and Considerations

  • No server-side mixing/transcoding: Videobridge forwards streams (SFU) rather than acting as an MCU; server-side transcoding requires separate components or external transcoders.
  • Prometheus coverage is substantial but not every internal metric is exposed in Prometheus format; some monitoring workflows rely on auxiliary exporters or the JSON/stats endpoints.
  • Performance and capacity depend on network, codec choices, and server sizing; achieving maximum concurrent streams requires tuning (heap, GC, networking) and appropriate deployment topologies.

Jitsi Videobridge is a mature, open-source SFU for teams and developers who need scalable WebRTC media routing with XMPP/REST control and production monitoring. It is widely used in the Jitsi ecosystem and can be integrated into custom conferencing solutions or deployed as part of a larger real-time communications stack.

3.1kstars
1kforks
#18
Openfire

Openfire

Openfire is an open source XMPP (Jabber) server for real-time messaging and collaboration, with a web admin console and a plugin ecosystem.

Openfire screenshot

Openfire is an open source real-time collaboration server that implements the XMPP (Jabber) protocol for instant messaging and presence. It is designed to be straightforward to deploy and administer while supporting scalable, standards-based messaging.

Key Features

  • XMPP server for messaging, presence, and roster management
  • Web-based administration console for configuration and user management
  • Multi-User Chat (MUC) support for group chatrooms
  • Extensible plugin architecture to add features and integrations
  • TLS support and configurable authentication options for secure deployments

Use Cases

  • Self-hosted team chat infrastructure based on open standards (XMPP)
  • Embedding XMPP messaging in custom applications and products
  • Running private group chat services for communities, schools, or organizations

Openfire is a mature XMPP server with an active ecosystem, making it a solid choice for standards-based messaging deployments that need extensibility and administrative control.

3kstars
1.4kforks
#19
Stoat

Stoat

Stoat is an open-source, self-hostable chat platform for communities and teams, offering text channels, permissions, moderation tools, and a web app.

Stoat screenshot

Stoat is an open-source chat and community platform (formerly known as Revolt) that provides text channels, direct messages, role/permission controls, moderation tools, and rich media support. The project is implemented as a modular Rust backend with companion services and a web-native client, designed for self-hosting and community-focused deployments.

Key Features

  • Modular Rust-based backend split into multiple crates (REST API, WebSocket events, file server, proxy, daemons) for separation of responsibilities and scalability.
  • Deployable with Docker Compose and Nix; includes Dockerfile and compose examples for local and production deployment environments.
  • Integrates common infra components documented in the repo: MongoDB for primary storage, Redis for transient/cache needs, MinIO (S3-compatible) for file storage, and RabbitMQ for messaging/queues.
  • Provides WebSocket and REST APIs, presence and event servers, a file server with S3-compatible storage handling, and Tenor proxy support for GIFs.
  • Web and desktop clients are supported; the repository and docs reference a web client workflow (build with Node/Yarn tooling) and platform downloads.
  • Fine-grained permissions, moderation and bot support aimed at community management; emphasis on privacy and GDPR-aligned practices.

Use Cases

  • Host community servers for gaming, hobby, or interest groups requiring channel-based chat and moderation tools.
  • Private team or organization chat deployments with self-hosted infrastructure and custom integrations.
  • Custom deployments that need S3-compatible file storage, event-driven messaging, and WebSocket-based real-time updates.

Limitations and Considerations

  • Real-time voice/video features have historically been limited or under active development; audio/voice support may be experimental or staged and can require additional infrastructure (example configs reference LiveKit).
  • Federation with external networks is not implemented by default and has been indicated as low priority; cross-server federation is not a built-in feature.
  • Self-hosting requires multiple supporting services (MongoDB, Redis, MinIO, RabbitMQ) and moderate operational knowledge; resource and orchestration planning is necessary for larger deployments.

Stoat is a production-focused, open-source alternative to proprietary chat platforms, built primarily in Rust with container-first deployment patterns. It targets communities and teams that want control over their data and infrastructure while providing modern chat features.

2.7kstars
304forks
#20
Tox

Tox

Tox is a decentralized, peer-to-peer communication system for encrypted messaging, voice/video calls, screen sharing, and file transfers without central servers.

Tox screenshot

Tox is a peer-to-peer (serverless) communication network and protocol used by messaging clients to provide private conversations without relying on central servers. It focuses on end-to-end encrypted chat and real-time audio/video features while keeping user identities based on cryptographic keys.

Key Features

  • Peer-to-peer networking without central servers for message routing
  • End-to-end encryption and authentication implemented via libsodium/NaCl primitives
  • Instant messaging with friend requests and contact-style identities (public-key based)
  • Encrypted voice and video calls (A/V support depends on client build)
  • Screen sharing and file sharing support in Tox clients
  • Group chats supported by the protocol and ecosystem clients

Use Cases

  • Private one-to-one messaging and calls without a hosted backend
  • Building custom bots or automation around the Toxcore client library API
  • Secure team or community group chats in environments where central servers are undesirable

Limitations and Considerations

  • The core library and network have historically been described as experimental and not formally audited as a complete system
  • Bootstrapping into the network requires known bootstrap nodes and proper client configuration

Tox is best viewed as the underlying protocol and core library (Toxcore) powering multiple desktop and mobile clients. It is a strong fit for users who want decentralized communications with modern encryption and a client ecosystem rather than a single hosted service.

2.6kstars
303forks

Why choose an open source alternative?

  • Data ownership: Keep your data on your own servers
  • No vendor lock-in: Freedom to switch or modify at any time
  • Cost savings: Reduce or eliminate subscription fees
  • Transparency: Audit the code and know exactly what's running