# CRUBAL > An open language and engine for data about any kind of thing. Everything is a key and a value. Stewarded by Infinite Token. The specification is CC-BY-4.0. Read the chapters as Markdown: - [1. Data and the value model](https://raw.githubusercontent.com/nes4less/crubal/main/spec/01-data.md) - [2. The text form](https://raw.githubusercontent.com/nes4less/crubal/main/spec/02-text.md) - [3. The JSON form](https://raw.githubusercontent.com/nes4less/crubal/main/spec/03-json.md) - [4. Facets](https://raw.githubusercontent.com/nes4less/crubal/main/spec/04-facets.md) - [5. Classes](https://raw.githubusercontent.com/nes4less/crubal/main/spec/05-classes.md) - [6. Rules](https://raw.githubusercontent.com/nes4less/crubal/main/spec/06-rules.md) - [7. Contracts](https://raw.githubusercontent.com/nes4less/crubal/main/spec/07-contracts.md) - [8. Provenance and logs](https://raw.githubusercontent.com/nes4less/crubal/main/spec/08-provenance.md) - [9. Intake and evidence](https://raw.githubusercontent.com/nes4less/crubal/main/spec/09-intake.md) - [10. Migrations](https://raw.githubusercontent.com/nes4less/crubal/main/spec/10-migrations.md) - [11. Packages](https://raw.githubusercontent.com/nes4less/crubal/main/spec/11-packages.md) - [12. Views](https://raw.githubusercontent.com/nes4less/crubal/main/spec/12-views.md) - [13. Conformance](https://raw.githubusercontent.com/nes4less/crubal/main/spec/13-conformance.md) ## Implementing it - [Conformance test corpus](https://github.com/nes4less/crubal/tree/main/corpus): 90 cases, level by level - [Reference implementation](https://github.com/nes4less/crubal/tree/main/packages/crubal): npm `@cruba/crubal` ## Standard packages - [CRUBAL core](https://crubal.com/core/package.json): `crubal.com/core` - [Units and currencies](https://crubal.com/units/package.json): `crubal.com/units` - [Products](https://crubal.com/product/package.json): `crubal.com/product` - [Services](https://crubal.com/service/package.json): `crubal.com/service` - [Commerce](https://crubal.com/commerce/package.json): `crubal.com/commerce` - [Media](https://crubal.com/media/package.json): `crubal.com/media`