# Licence

## Open Database Licence (ODbL)

OpenChemFacts data is available under the [Open Data Commons Open Database Licence](https://opendatacommons.org/licenses/odbl/summary/) (ODbL).

The ODbL was created and is maintained by the Open Knowledge Foundation, a non-profit-making
 organisation.

It's designed to promote the free and open sharing of databases while ensuring that contributors and the community receive proper recognition.

The full legal text of the Open Database License (ODbL) v1.0 is available at:\
<https://opendatacommons.org/licenses/odbl/1-0/>

## What you can do&#x20;

Under the ODbL, you are free to:

* **Share** — copy, distribute and use the database
* **Create** — produce works from the database
* **Adapt** — modify, transform and build upon the database

These freedoms apply for **any purpose**, including commercial use.

## What you must respect

When using OpenChemFacts data, you must comply with the following obligations:

1. **Attribution**\
   You must attribute OpenChemFacts as the source of the data. Attribution should be reasonable and clearly visible, for example by mentioning *“Data © OpenChemFacts contributors, licensed under ODbL”*.
2. **Share-Alike**\
   If you publicly share a modified version of the database, or a database derived from it, you must distribute it under the **same ODbL license**.
3. **Keep the Data Open**\
   If you use the database in a way that results in a publicly accessible database or service, you must ensure that users can access the underlying data under ODbL terms.

## Produced Works vs. Derived Databases

The ODbL distinguishes between:

* **Produced Works** (e.g. analyses, visualizations, reports, or applications built using the data) : \
  These are *not* required to be licensed under ODbL, as long as the underlying database itself is not redistributed.
* **Derivative Databases** (e.g. enriched, filtered, or merged datasets) :\
  These must be shared under the ODbL if they are made publicly available.

## Why ODbL ?

The ODbL ensures that OpenChemFacts data remains:

* **Open and reusable**
* **Protected against proprietary enclosure**
* **Enriched by community contributions**

By using OpenChemFacts data, you agree to respect these principles and contribute to a sustainable open data ecosystem.