Ontology Playground

Overview

Ontology Playground is a free, MIT-licensed web app from Microsoft (repo microsoft/Ontology-Playground, live at microsoft.github.io/Ontology-Playground) for learning ontologies and Microsoft Fabric IQ. It is a fully static site: explore pre-built ontologies, design your own visually, export RDF/XML and share or embed interactive diagrams. The README states it was developed with AI-assisted coding and labels the project “(Preview)“. As of 2026-10-02 the repo shows about 2.8k GitHub stars (2.83k via GitHub API 2026-10-05; last push 2026-09-17) (the 14 stars in the earlier version of this note were outdated). Stack: React 19, TypeScript 5, Cytoscape.js, Zustand, Vite, Framer Motion.

Ontology concepts it teaches

Entity types, properties (typed facts), relationships (typed, directional, with cardinality), constraints, data bindings to OneLake sources, and the instance graph built from them. This is Fabric IQ’s ontology vocabulary, used as a shared semantic layer so humans and AI agents reason over the same business meaning.

Features (README, 2026-10-02)

• Catalogue: official and community ontologies in six domains (Retail, E-Commerce, Healthcare, Finance, Manufacturing, Education), deep-linkable, with one-click pull request submission.
• Visual designer: split-pane editor with live graph preview, undo/redo, RDF/XML (OWL) import and export in the format Fabric IQ expects.
• Embeddable widget: a single script renders an ontology viewer on any page.
• Ontology School: 9 courses = 6 fundamentals articles + 7 domain learning paths (Fourth Coffee, E-Commerce, Finance, Healthcare, Manufacturing, University, HR System) + an “IQ Lab: Retail Supply Chain” (7 steps, 15-entity ontology). Presentation mode with quizzes.
• Quests: 5 guided quests.
• Natural-language query playground: previews how questions map to ontology entities (illustrates Fabric IQ’s NL-to-ontology idea; not the product itself).
• Optional Azure OpenAI ontology builder behind a feature flag (off by default).

Relationship to Fabric IQ

Fabric IQ, Microsoft’s semantic layer for AI agents on Fabric data, is described on Microsoft Learn (page updated 2026-09-29, read 2026-10-05) as part of Microsoft IQ, delivered as an “IQ (preview)” workload whose core items are the ontology (preview) and the Power BI semantic model. Community and partner posts claiming Fabric IQ reached general availability at Build 2026 are not reflected in the Learn docs: treat the ontology item as preview. The Playground is a learning and authoring aid, not a production runtime; no data is bound or queried.

Strengths and limits

Strengths (opinion): no backend, visual, RDF/XML import and export, teaching material included. Limits (opinion): tied to Fabric IQ conventions; catalogue managed through GitHub PRs; designing a good ontology still requires modelling skill.

Related

graphrag, Neo4j (graph databases often hold instance data for ontologies), ai-memory.

Open items

• Re-check Fabric IQ GA/preview wording on Microsoft Learn periodically; it changes.
• Earlier-note details (Azure Static Web Apps deployment, env vars, contributor names, project structure) were dropped as unverified and low value; re-check the repo if needed.

Sources

• https://github.com/microsoft/Ontology-Playground and its README (accessed 2026-10-02)
• https://microsoft.github.io/Ontology-Playground/ (not opened; URL from README)
• https://learn.microsoft.com/en-us/fabric/iq/overview (accessed 2026-10-05)
• https://kanerika.com/blogs/microsoft-fabric-iq/ and https://community.fabric.microsoft.com/blog/fiq_comm_blog/fabric-iq-is-ga-your-ontology-isnt-heres-what-that-actually-means-/5364087 (search snippets, accessed 2026-10-02)