MDN Web Docs is an evolving learning platform for Web technologies and the software that powers the Web, including:
MDN's mission is simple: to provide developers with the information they need to easily build projects on the open Web. If it's an open technology exposed to the Web, we want to document it.
If you're not sure whether a particular topic should be covered on MDN, read: Does this belong on MDN?
How you can help
You don't need to be able to code—or to write well—in order to be able to help MDN! We have lots of ways you can help, from reviewing articles to be sure they make sense, to contributing text, to adding sample code. In fact, there are so many ways to help that we have a Getting Started page that helps you pick tasks to do, based on your interests and how much time you have to spare!
You can also help by promoting MDN on your own blog or website.
The MDN community
Our community is a global one! We have amazing contributors all around the world, in a number of languages. If you'd like to learn more about us, or if you need help of any kind with MDN, feel free to check out our discussion forum or IRC channel! You can also keep up with what we're up to by following our Twitter account, @MozDevNet. You can also send tweets our way if you see something wrong or if you'd like to offer feedback (or great big thank yous) to our writers and contributors!
Using MDN Web Docs content
MDN's content is available free of charge, and under open source licenses.
Copyrights and licenses
MDN's content is entirely available under various open source licenses. This section covers the types of content we provide and what licenses are in effect for each.
Documentation and articles
MDN wiki documents have been prepared with the contributions of many authors, both within and outside the Mozilla Foundation. Unless otherwise indicated, the content is available under the terms of the Creative Commons Attribution-ShareAlike license (CC-BY-SA), v2.5 or any later version. Please attribute "Mozilla Contributors" and include a hyperlink (online) or URL (in print) to the specific wiki page for the content being sourced. For example, to provide attribution for this article, you can write:
About MDN by Mozilla Contributors is licensed under CC-BY-SA 2.5.
Note that in the example, "Mozilla Contributors" links to the history of the cited page. See Best practices for attribution for further explanation.
See MDN content on WebPlatform.org for information about how to reuse and attribute MDN content on that site.
Code samples and snippets
Code samples added on or after August 20, 2010 are in the public domain (CC0). No licensing notice is necessary, but if you need one, you can use: "Any copyright is dedicated to the Public Domain. http://creativecommons.org/publicdomain/zero/1.0/".
Code samples added to this wiki before August 20, 2010 are available under the MIT license; you should insert the following attribution information into the MIT template: "© <date of last wiki page revision> <name of person who put it in the wiki>".
You can determine when a sample was added to MDN by browsing through the article's history using the "History" option in the gear-shaped drop-down menu at the top-right corner of the screen. The easiest way to track this down is by doing a binary search, going back to the beginning of the article, looking to see if the sample is there, then going to the halfway point, looking there, then halfway between, and so forth. Once you find the revision that added the sample, look at its date, then compare the date to those described above to determine whether the code is licensed under CC0 or MIT.
If you wish to contribute to this wiki, you must make your documentation available under the Attribution-ShareAlike license (or occasionally an alternative license already specified by the page you are editing), and your code samples available under Creative Commons CC-0 (a Public Domain dedication). Adding to this wiki means you agree that your contributions will be made available under those licenses.
Some older content was made available under a license other than the licenses noted above; these are indicated at the bottom of each page by way of an Alternate License Block.
No new pages may be created using alternate licenses.
Copyright for contributed materials remains with the author unless the author assigns it to someone else.
If you have any questions or concerns about anything discussed here, please contact the MDN administrators.
Logos, trademarks, service marks and wordmarks
The rights in the trademarks, logos, service marks of the Mozilla Foundation, as well as the look and feel of this web site, are not licensed under the Creative Commons license, and to the extent they are works of authorship (like logos and graphic design), they are not included in the work that is licensed under those terms. If you use the text of documents, and wish to also use any of these rights, or if you have any other questions about complying with our licensing terms for this collection, you should contact the Mozilla Foundation here: firstname.lastname@example.org.
Linking to MDN
See this article for guidance on linking to MDN for best practices when linking.
You can download a full tarball mirror of MDN (2.1 GB as of February 2017).
You can retrieve the content of a single page on MDN by adding URL parameters to specify what format you want.
Reporting problems with MDN Web Docs
History of MDN Web Docs
The MDN Web Docs (previously Mozilla Developer Network (MDN), previously Mozilla Developer Center (MDC), a.k.a. Devmo) project started in early 2005, when the Mozilla Foundation obtained a license from AOL to use the original Netscape DevEdge content. The DevEdge content was mined for still-useful material, which was then migrated by volunteers into this wiki so it would be easier to update and maintain.
You can find more history of MDN on our 10th anniversary celebration page, including an oral history by some of the people who were involved.
Whether you want to learn more about who we are, how to be a part of Mozilla or just where to find us, you've come to the right place. To find out what drives us and makes us different, please visit our mission page.