Permanent Identifiers for the Web

Web applications that deal with data on the web often need to specify and use URLs that are very stable. They utilize services such as purl.org to ensure that applications using their URLs will always be re-directed to a working website. These “permanent URL” redirection services operate kind of like a switchboard, connecting requests for information with the true location of the information on the Web. These switchboards can be reconfigured to point to a new location if the old location stops working.

How Does it Work?

If the concept sounds a bit vague, perhaps an example will help. A web author could use the following link (https://w3id.org/payswarm/v1) to refer to an important document. That link is hosted on a permanent identifier service. When a Web browser attempts to retrieve that link, it will be re-directed to the true location of the document on the Web. Currently, that location is https://payswarm.com/contexts/payswarm-v1.jsonld. If the location of the payswarm-v1.jsonld document changes at any point in the future, the only thing that needs to be updated is the re-direction entry on w3id.org. That is, all Web applications that use the https://w3id.org/payswarm/v1 URL will be transparently re-directed to the new location of the document and will continue to “Just Work™”.

w3id.org Launches

Permanent identifiers on the Web are an important thing to support, but until today there was no organization that would back a service for the Web to keep these sorts of permanent identifiers operating over the course of multiple decades. A number of us saw that this is a real problem and so we launched w3id.org, which is a permanent identifier service for the Web. The purpose of w3id.org is to provide a secure, permanent URL re-direction service for Web applications. This service will be run and operated by the W3C Permanent Identifier Community Group.

Specifically, the following organizations that have pledged responsibility to ensure the operation of this service for the decades to come: Digital Bazaar, 3 Round Stones, OpenLink Software, Applied Testing and Technology, and Openspring. Many more organizations will join in time.

These organizations are responsible for all administrative tasks associated with operating the service. The social contract between these organizations gives each of them full access to all information required to maintain and operate the website. The agreement is setup such that a number of these companies could fail, lose interest, or become unavailable for long periods of time without negatively affecting the operation of the site.

Why not purl.org

While many web authors and data publishers currently use purl.org, there are a number of issues or concerns that we have about the website:

  1. The site was designed for the library community and was never intended to be used by the general Web.
  2. Requests for information or changes to the service frequently go unanswered.
  3. The site does not support HTTPS connections, which means it cannot be used to serve documents for security-sensitive industries such as medicine and finance. Requests to migrate the site to HTTPs have gone unanswered.
  4. There is no published backup or fail-over plan for the website.
  5. The site is run by a single organization, with a single part-time administrator, on a single machine. It suffers from multiple single points of failure.

w3id.org Features

The launch of the w3id.org website mitigates all of the issues outlined above with purl.org:

  1. The site is specifically designed for web developers, authors, and data publishers on the general Web. It is not tailored for any specific community.
  2. Requests for information can be sent to a public mailing list that contains multiple administrators that are accountable for answering questions publicly. All administrators have been actively involved in world standards for many years and know how to run a service at this scale.
  3. The site supports HTTPS security, which means it can be used to securely serve data for industries such as medicine and finance.
  4. Multiple organizations, with multiple administrators per organization have full access to administer all aspects of the site and recover it from any potential failure. All important site data is in version control and is mirrored across the world on a regular basis.
  5. The site is run by a consortium of organizations that have each pledged to maintain the site for as long as possible. If a member organization fails, a new one will be found to replace the failing organization while the rest of the members ensure the smooth operation of the site.

All identifiers associated with the w3id.org website are intended to be around for as long as the Web is around. This means decades, if not centuries. If the final destination for popular identifiers used by this service fail in such a way as to be a major inconvenience or danger to the Web, the community will mirror the information for the popular identifier and setup a working redirect to restore service to the rest of the Web.

Adding a Permanent Identifier

Anyone with a github account and knowledge of simple Apache redirect rules can add a permanent identifier to w3id.org by performing the following steps:

  1. Fork w3id.org on Github.
  2. Add a new redirect entry and commit your changes.
  3. Submit a pull request for your changes.

If you wish to engage the community in discussion about this service for your Web application, please send an e-mail to the [email protected] mailing list. If you are interested in helping to maintain this service for the Web, please join the W3C Permanent Identifier Community Group.


Note: The letters ‘w3’ in the w3id.org domain name stand for “World Wide Web”. Other than hosting the software for the Permanent Identifier Community Group, the “World Wide Web Consortium” (W3C) is not involved in the support or management of w3id.org in any way.

Source: Manu Sporny

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