Open source diagram projects
Every project in the registry tagged diagram, ranked by real GitHub adoption.
Free instant whiteboard with real-time collaboration
Security-first diagramming with no login required
FlowGram is an extensible workflow development framework with built-in canvas, form, variable, and materials that helps developers build AI workflow platforms f
Answer me with HTML — an agent skill that answers hard questions with a one-page HTML you can actually read. 让 AI Agent 用一页 HTML 回答复杂问题。
Angular-native node editor library for production workflow builders, AI pipelines, and interactive diagram editors. MIT licensed.
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Frequently asked questions
How many open source diagram projects are there?
This registry tracks 5 projects tagged diagram, with 74,521 GitHub stars between them. The most-adopted is Tldraw at 51,207 stars.
Are these diagram projects free to use?
Yes — 4 of the 5 carry an explicit open-source licence across 2 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.
Which diagram project should I choose?
The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.
Are these diagram projects still maintained?
5 of the 5 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.