After a year of (off and on) development we are delighted today to announce the official launch of the Comprehensive Knowledge Archive Network (CKAN for short):

CKAN is a registry of open knowledge packages and projects — be that a set of Shakespeare’s works, a global population density database, the voting records of MPs, or 30 years of US patents.

CKAN is the place to search for open knowledge resources as well as register your own. Those familiar with freshmeat (a registry of open source software), CPAN (Perl) or PyPI (python package index) can think of CKAN as providing an analogous service for open knowledge.

CKAN is a key part of our long-term roadmap and completes our work on the first layer of open knowledge tools:

CKAN links in especially closely with our recent discussions of componentization: we envision a future in which open knowledge is provided in a much more componentized form (packages) so as to facilitate greater reuse and recombination similar to what occurs with software today (see the recent XTech presentation for more details). For this to occur we need to make it much easier for people to share, find, download, and ‘plug into’ the open knowledge packages that are produced. An essential first step in achieving this is to have a metadata registry where people can register their work and where relevant metadata (both structured and unstructured) can be gradually added over time.

We also make no bones that fact what we have is present is very simple, certainly when compared to the long-term vision — after all, we should remember it has taken software over thirty years to reach its present level of sophistication. Thus, rather than attempting to pre-judge the solution to open knowledge componentisation question (for example in the choice of metadata attached to each package), this beta version is the simplest possible thing that will provide value, and we look to user feedback (and we include ourselves here as users) to determine the future direction of development of the system.


What kinds of things do you expect people to register in CKAN?

Anything and everything — when we say knowledge we mean any kind of content, data or information. That said there are two main recommendations regarding what you register:

  • First, we are looking for people to register ‘packages’ that is collections with some kind of structure rather than individual items. So a substantial set of photos, a datasets of all kinds, the writings of Shakespeare but not an individual blog, or your flickr photo collection (unless it is really big!).
  • Second, we’re looking for stuff that’s open: that is material that people are free to use, reuse and redistribute without restriction (other than, perhaps, a requirement to share-alike).

Why Not Just Use the Creative Commons Search Facility in Google/Yahoo/etc

Two main reasons:

  1. We focus on work that is open. Simply put the set of open work and the set of CC-licensed works are not identical because (a) not all Creative Commons licensed work is open (for example those which use the non-commercial provision are not) and (b) there are plenty of open works which do not use CC licenses (e.g. Wikipedia)

  2. The registry is designed to support holding much more metadata than simply whether the work is open on not. In particular we want to be able to support automated installation of knowledge packages in the future (which requires things like dependency and version information).

Is CKAN itself open?

Of course, both the code that CKAN runs on and the data itself is open, see the license page:

How Can I Get Involved

Start enter things into CKAN and editing existing entries — you don’t need to be the developer of a particular project or resource to enter it into the registry.

If you want to get more deeply involved join the okfn-discuss list and and introduce yourself or just drop an email to info [at] okfn [dot] org. If you want to just start hacking with the code see our development project page (then follow the links to subversion):

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Rufus Pollock is Founder and President of Open Knowledge.

5 thoughts on “The Comprehensive Knowledge Archive Network (CKAN) Launched Today”

  1. What’s the situation for data which perhaps should be free, but isn’t?

    e.g. TheyWorkForYou when first launched didn’t have a license, and breached Parliamentary copyright. I’m guessing that data would have no place in the registry?

    Even now, if you use TheyWorkForYou’s data you should probably go and get a click-use license from OPSI. I don’t think it meets the OKD, even though it ought to be data that does.

    However, I guess some of our analyses of the semi-closed data are free.

  2. While CKAN is targeted at stuff that is open you can still post some stuff that isn’t — in fact there is special drop-down item in the license list for this option. After all, it is valuable to know what resources are out there and might potentially be open (a lot of material , especially data, simply lacks any kind of explicit license and I hope one consequence of starting to list this stuff is that it will facilitate going and asking people to open it up).

    Turning to the specific example of TheyWorkForYou data. At the start, when the status of the material was unclear, you could have still entered in the registry though to be on the safe side you should have left the license field blank (and perhaps added a tag such as ‘status-uncertain’).

    If it is now click-use licensable that’s even better because then it really is open (the standard UK click-use license is open and does meet the OKD — see the listing on

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