Showing 8 results
Excalidraw
Virtual whiteboard — hand-drawn diagrams, real-time collaboration.
MIT-licensed alternative to Miro with E2EE collaboration, component library, and export to PNG/SVG/JSON. React npm package for embedding.
Rocket.Chat
Self-hosted team messaging — channels, video, and compliance.
MIT-licensed alternative to Slack and Mattermost with end-to-end encryption, Omnichannel, apps marketplace, and FedRAMP-ready compliance.
Mattermost
Secure team collaboration — messaging, playbooks, and integrations.
MIT-licensed alternative to Slack with channels, threads, webhooks, Jira/GitHub integrations, and Playbooks for incident response. Desktop and mobile apps.
Nextcloud
Self-hosted cloud — files, calendar, mail, and office suite.
AGPL-3.0 alternative to Dropbox with 300+ apps, Collabora/OnlyOffice integration, Talk video conferencing, and end-to-end encryption.
Zulip
Topic-threaded team chat — keeps conversations organized at scale.
Zulip is an open-source team chat application built around topic-based threading, which keeps conversations organized in a way that channel-only tools like Slack or Rocket.Chat don't. Apache-2.0 licensed and self-hostable.
Element
Matrix-based team messaging — decentralized and end-to-end encrypted.
Element is an open-source, end-to-end encrypted collaboration client built on the decentralized Matrix protocol, so it can federate across independent servers rather than relying on one company's infrastructure. AGPL-3.0 licensed.
Campfire
Simple self-hosted group chat from 37signals — one-time, MIT-licensed, no subscription.
Campfire is a simple, self-hosted group chat application from 37signals, released as open source under the MIT license in 2025. It's deliberately minimal — @mentions, DMs, rooms — with no recurring subscription.
Wire
End-to-end encrypted team collaboration — messaging, calls, EU-based.
Wire is an open-source, end-to-end encrypted collaboration platform for messaging, calls, and file sharing, aimed at organizations with strong security and compliance requirements. AGPL-3.0 licensed, based in the EU.
Excalidraw is a whiteboarding tool, while Rocket.Chat, Mattermost, and Nextcloud cover team messaging and self-hosted collaboration more broadly.
For real-time team messaging, Rocket.Chat and Mattermost are closest to each other — Rocket.Chat leans toward omnichannel and compliance features, Mattermost toward developer workflows and playbooks. Nextcloud is broader still, combining files, calendar, mail, and messaging in one self-hosted suite. Excalidraw is a focused whiteboarding tool, not a messaging platform.
FAQ
What's the best open-source alternative to Slack or Microsoft Teams?
Rocket.Chat or Mattermost for dedicated team messaging. See alternatives to Slack and alternatives to Microsoft Teams.
What's the best open-source alternative to Miro?
Excalidraw covers hand-drawn diagrams and real-time whiteboarding. See alternatives to Miro.
Is there an open-source alternative to Dropbox or Google Drive that also includes messaging?
Nextcloud combines file storage, calendar, mail, and office tools in one self-hosted suite. See alternatives to Dropbox and alternatives to Google Drive.
What are the top open-source collaboration tools?
Browse alternatives to Slack, alternatives to Miro, and alternatives to Dropbox above for more options.