The best open source Team Collaboration alternative to Slack is Element. It's not free, so if you're looking for a free alternative, you could try Element or Zulip. If that doesn't suit you, our users have ranked more than 100 alternatives to Slack and many of them are open source Team Collaboration Tools so hopefully you can find a suitable replacement. Other interesting open source Team Collaboration Tool alternatives to Slack are Matrix, Stoat Chat, Element X and Twake.
Provides secure collaboration with end-to-end encryption, supporting chat, voice, and video calls. Available on all major platforms, it enables digital sovereignty with a decentralized design and interoperability through bridges to systems like Slack and Teams. Includes enterprise-grade SaaS.
Threaded group conversations combine live and asynchronous messaging, separating topics for organized collaboration, supporting open-source, cloud, and self-hosted deployments, secure communication with encryption, and multi-platform access for diverse teams.
Open-source chat server supporting real-time group, direct, and private messaging, video calls, file sharing, helpdesk chat, API integrations, desktop notifications, emojis, LDAP authentication, cross-platform apps, and customizable extensions for teams.
Open standard protocol enabling decentralized, encrypted instant messaging, VoIP signaling, IoT device connectivity, and persistent data management across federated servers without central control or single points of failure, bridging communication platforms.
Instant messaging platform supporting text and voice channels, live video calls, secure screen sharing, private group chats, customizable permissions, moderation tools, bot integration, privacy-focused design, open-source development, and cross-platform use.
It is the brand new, and fastest ever, Matrix client. It is for personal and community use, and will support enterprise functionality later this year.
Twake is a real-time teamwork platform. It is a suite of collaborative tools that includes the specificities of some bestsellers (Slack, Trello, Google Drive...). We provide professional messaging, storage space, online collaborative editors (Words, Excel, PowerPoint), task...
Open-source platform unifying project, document, issue, and task management with real-time team collaboration, instant messaging, video conferencing, and GitHub bidirectional sync, all in one customizable workspace for developers and product teams.
The best Discord alternative. Mezon is a Live, Work, and Play platform. It’s perfect for gaming and chilling with friends, or even building a global community. Customize your own space to talk, play, and hang out.
Decentralized chat platform built on the nostr protocol with support for multi-group communities, event calendars, threads, private messaging, web of trust, customizable access controls, monetization via zaps, full privacy, and white-label options for branding.
All you need in a team collaboration tool dedicated to small efficient teams. Chat, notes, drive, online collaborative edition, calendars, news, spaces, notifications...
eXo Platform is an all-in-one digital workplace solution that helps you connect, align and engage your teams around a single interface. You can use it to improve company and peer-to-peer communication, boost collaboration and manage company knowledge.
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because its open source, decentralised, and end-to-end secure. Plus the folks at matrix.org are working to get us out of our communication silos by creating standards for communication interoperability!