In order to promote efficient access to W3C content the W3C Webmaster Team has deployed mirrors on several continents: North America, Asia, Europe.

Mirroring

This document is out-of-date and needs review by W3C.

Presently all mirrors are under the control of the W3C. W3C is currently not granting permission to other parties to run mirrors of W3C sites. You are welcome to maintain copies of W3C resources as outlined in our W3C Document License.

Some of the challenges to mirroring include:

• Mirroring the W3C Site with tools such as wget is inadequate: documents are constantly changing and that would mean that the mirror would constantly be out-of-date.
• Changes on the site should appear on all the mirrors at the same time.
• The W3C must ensure that content is up to date and served in accordance with W3C trademark, copyright, privacy, and administrative policies. Furthermore, the W3C will clearly define the responsibilities and liabilities associated with those policies -- and their abuse. As an example, sites that don't abide by our privacy policies may be subject to civil or even criminal prosecution in some jurisdictions.

Caching of W3C materials

Caching of W3C materials should comply with the "maximum time to live" information provided with the materials. After such materials have expired they should not be served from shared caches without first validating the contents of the W3C Site. For more on HTTP caching, see RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1.