Open Source Collaboration & Communication Tools using CSS

A curated collection of the best free and open source tools for teams working together, covering chat, shared documents, whiteboards and meetings using CSS.

Excalidraw

An open source virtual whiteboard for hand-drawn style diagrams and wireframes, collaborative, end-to-end encrypted and embeddable as an npm package.

Alternative to:

Lucidchart

Collaborative whiteboard with a hand-drawn aesthetic

Stars
134,677
Forks
15,864
Last commit
23 hours ago

Affine

An all-in-one workspace merging documents, whiteboards and databases, built local-first for teams that want to own their knowledge base.

Alternative to:

Notion

Docs, whiteboards, and databases in one privacy-first workspace

Stars
73,918

Buzz

Self-hostable workspace where people and AI agents share the same channels, built on a Nostr relay with a signed event log.

Alternative to:

Slack

Team chat, project management, and AI agents in one place

Stars
36,523

Tldraw

A React SDK for building infinite canvas apps, shipping a whiteboard out of the box and custom shapes when you need them.

Alternative to:

Miro

Free instant whiteboard with real-time collaboration

Stars
51,120

Rocket.Chat

A self-hosted communications platform for organizations with strict data protection needs, covering messaging, voice, federation and customer conversations.

Alternative to:

Slack

Self-hosted team messaging with voice, video, and AI

Stars
46,343

Mattermost

Self-hosted collaboration platform with chat, workflow automation, voice calling and screen sharing for teams that must control their own deployment.

Alternative to:

Slack

Secure collaboration platform for mission-critical work

Stars
39,454

Nextcloud

Self-hosted platform for files, contacts and calendars, giving organizations and individuals a place to store and share data on their own server.

Alternative to:

Dropbox

Secure cloud collaboration platform for organizations

Stars
37,321

Zulip

Team chat organized by topic inside each channel, built for distributed teams that mix live conversation with asynchronous catch-up.

Alternative to:

Slack

Organized team chat for distributed teams

Stars
26,125

Jitsi

A set of open source projects for running video conferences in the browser, self-hosted or on a free public instance.

Alternative to:

Microsoft Teams

Private, secure video calls with no account needed

Stars
30,157

Teable

A PostgreSQL-backed database that works like a spreadsheet, with AI chat and an app builder, for teams building internal tools.

Alternative to:

Coda

Flexible database meets intuitive spreadsheet interface

Stars
21,932

Docs

Collaborative text editor for teams writing and organizing knowledge together, built by the French and German public administrations.

Alternative to:

Notion

Create, edit and share documents with real-time collaboration

Stars
16,952

Element

A Matrix client for the web and desktop, giving teams and individuals decentralized chat they are free to host themselves.

Alternative to:

Slack

Secure, decentralized messaging for teams and individuals

Stars
13,620

Fluxer

A free and open source instant messaging and VoIP chat app for friends, groups and communities, with a fully self-hostable backend.

Alternative to:

Discord

Open source messaging with privacy and community focus

Stars
10,688

Campfire

Web-based team chat with rooms, direct messages and file previews, packaged as one Docker image for a single machine.

Alternative to:

Slack

Self-hosted group chat without recurring subscription fees

Stars
4,805

Workadventure

A customizable virtual world where teammates move as avatars and video chat starts the moment they walk up to each other.

Alternative to:

Gather

Virtual office platform for engaging remote collaboration

Stars
5,888

Colanode

Local-first collaboration workspace you self-host, combining chat, wiki pages, databases, and file storage for teams that want to own their data.

Alternative to:

Notion

Self-hosted team workspace with chat, docs, and databases

Stars
5,177

Cinny

Matrix client built around a simple, elegant interface, available as a hosted web app, a desktop build or a static site you serve yourself.

Alternative to:

Slack

Secure and elegant Matrix client for seamless conversations

Stars
3,947

Mezon

A real-time communication platform for gaming, work, and community spaces, with native clients and a C server stack built for low latency.

Alternative to:

Slack

Create custom spaces to chat, game, and connect globally

Stars
2,011

UnInbox

Open source email built for teams, with shared spaces, per-conversation workflow statuses and unlimited addresses, for anyone drowning in shared inboxes.

Alternative to:

Front

Transform team email into efficient collaborative workflows

Stars
1,760

Ever Teams

Work and project management platform with time and activity tracking, for teams that want to run their own instance.

Alternative to:

Asana

Real-time work and project management platform

Stars
599

dDocs

End-to-end encrypted document editor for teams that want Google Docs style collaboration without handing the contents to a hosted service.

Alternative to:

Notion

End-to-end encrypted collaborative document editor

Stars
450

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Open Source Collaboration & Communication Tools using CSS

A curated collection of the best free and open source tools for teams working together, covering chat, shared documents, whiteboards and meetings using CSS.

Excalidraw

Affine

Buzz

Tldraw

Rocket.Chat

Mattermost

Nextcloud

Zulip

Jitsi

Teable

Docs

Element

Fluxer

Campfire

Workadventure

Colanode

Cinny

Mezon

UnInbox

Ever Teams

dDocs

Excalidraw

Affine

Buzz

Tldraw

Rocket.Chat

Mattermost

Nextcloud

Zulip

Jitsi

Teable

Docs

Element

Fluxer

Campfire

Workadventure

Colanode

Cinny

Mezon

UnInbox

Ever Teams

dDocs

Plane