Collaboration

4 open source tools compared. Sorted by stars — scroll down for our analysis.

Tool	Stars	Velocity	Language	License	Score
Excalidraw Virtual whiteboard for sketching hand-drawn diagrams	119.5k	—	TypeScript	MIT License	82
AppFlowy Open source Notion alternative	68.8k	—	Dart	GNU Affero General Public License v3.0	74
tldraw SDK for creating whiteboards and canvas experiences	46.0k	—	TypeScript	—	69
drawnix	13.3k	—	TypeScript	—	65

Our Analysis

Excalidraw119.5k★

Excalidraw makes diagrams that look hand-drawn, and that's exactly why people love it. No perfectly straight lines, no corporate clip art — just sketchy boxes and arrows that feel like a whiteboard session. It's become the default diagramming tool for technical blog posts and architecture discussions. Mermaid generates diagrams from text (great for docs, bad for freeform). draw.io is the structured alternative with more shapes and precision. tldraw is the newer hand-drawn competitor. Figma is the commercial design tool that can do diagrams but is overkill. Use Excalidraw for architecture sketches, blog illustrations, and any diagram where approachability matters more than pixel perfection. The library version embeds in React apps. MIT licensed, runs entirely in the browser with optional collaboration. The catch: it's intentionally limited. No advanced shapes, no auto-layout, no data-driven diagrams. Complex system architectures with 50+ components will be messy. And the hand-drawn style, while charming, isn't appropriate for formal documentation or client presentations.

AppFlowy68.8k★

AppFlowy is the open source Notion alternative that actually respects local-first. Your data lives on your device, syncs optionally, and you can self-host the backend. Built in Rust and Flutter, it's genuinely cross-platform and offline-capable. Notion is the feature-complete commercial standard but holds your data hostage. Obsidian is the power-user knowledge base — Markdown files, plugin ecosystem, but no database views. AnyType is another local-first option with a smaller community. If you want Notion's docs-plus-databases workflow without sending everything to someone else's servers, AppFlowy is the closest you'll get. The desktop experience is solid and improving fast. AGPL licensed, so self-hosting is encouraged. The catch: the mobile app is noticeably behind Notion's polish. Third-party integrations are limited — no Zapier, no Slack, no calendar sync. AI features are on the roadmap but not production-ready. And AGPL means if you build a hosted service on AppFlowy, you're open-sourcing your modifications.

tldraw46.0k★

The best infinite canvas SDK for React, and it's not close. tldraw gives you a complete whiteboard — drawing tools, shapes, connectors, real-time collaboration — as an embeddable React component. If you're building a product that needs canvas or diagramming features, this saves months of work. Excalidraw is the popular standalone whiteboard but harder to embed as an SDK. Fabric.js is lower-level canvas manipulation. Konva handles React canvas but without whiteboard features. Miro and FigJam are the commercial alternatives. The SDK is remarkably polished: custom shapes, tools, and interactions are well-documented. The 46K+ stars reflect genuine developer enthusiasm, and the $10M Series A means active development. The catch: the license changed significantly in v4.0. Production use now requires a commercial license — the SDK is free for development and education only. This means if you're building a product with tldraw embedded, you need to talk to sales before shipping. The starter kits remain MIT, but the core SDK does not. Budget accordingly.