Virtual whiteboard for sketching hand-drawn like diagrams

The communications platform that puts data protection first.

very good whiteboard SDK / infinite canvas SDK

Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..

Focalboard is an open source, self-hosted alternative to Trello, Notion, and Asana.

AI-powered development workspaces with reusable components, architectural clarity and zero overhead.

Etherpad: A modern really-real-time collaborative document editor.

⚡️⚡️⚡️ Self-hosted collaborative bookmark manager to collect, read, annotate, and fully preserve what matters, all in one place.

Open-source feature management platform

Build truly AI-native spreadsheets. Univer is a full-stack framework for creating and editing spreadsheets, documents, and slides on both web and server. With Univer MCP, Univer Sheet is driven directly through natural language.

HedgeDoc - Ideas grow better together

开源白板工具（SaaS），一体化白板，包含思维导图、流程图、自由画等。All in one open-source whiteboard tool with mind, flowchart, freehand and etc.

PartyKit simplifies developing multiplayer applications

🧩 Content editing tech stack for the web - BlockSuite is a toolkit for building editors and collaborative applications.

Library for building distributed, real-time collaborative web applications

The best apps in the AI era aren’t solo experiences—they’re collaborative. Liveblocks provides customizable pre‑built features to make your product multiplayer, engaging, and AI‑ready. All without derailing your roadmap.

Lightweight Google-searchable Slack alternative for Communities

Open source video conferencing system for tutors.

a Restful Api test tool

Open-source developer content platform