Open Source

At the Open Knowledge Foundation we believe strongly that open data is best served with open tools. CKAN is open source, free software. This means that you can use it without any license fees, but more importantly, when you choose CKAN for your catalog you are also ensuring that you retain all rights to the data and metadata you enter, giving you freedom to move it elsewhere or manipulate it with your own tools without restriction.

There are lots of different open source licenses (you can find them at http://opensource.org) – CKAN is licensed specifically under the terms of the Affero GNU GPL v3.0.

One of the strengths of the open source model is in the communities that form around free software products. The CKAN community is no different, and is arguably one of the strongest open data communities in the world. Together, the CKAN community has a wealth of knowledge and expertise that other people using the CKAN software can draw on. The Open Knowledge Foundation draw on and contribute to this rich resource to help us drive CKAN product development.

Technology

CKAN is built with Python on the backend and Javascript on the frontend, and uses the Pylons web framework and SQLAlchemy as its ORM. Its database engine is PostgreSQL and its search is powered by SOLR. It has a modular architecture that allows extensions to be developed to provide additional features such as harvesting or data upload.

CKAN uses its internal model to store metadata about the different records, and presents it on a web interface that allows users to browse and search this metadata. It also offers a powerful API that allows third-party applications and services to be built around it.

Resources & links

• Developer mailing list: http://lists.okfn.org/mailman/listinfo/ckan-dev
• CKAN discussion mailing list: http://lists.okfn.org/mailman/listinfo/ckan-discuss
• Developer documentation: http://docs.ckan.org/
• Public Trac tickets: http://trac.ckan.org/
• Code repo: https://github.com/okfn/ckan