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Implementation Evidence

In the Chairs initial decision, a number of arguments and counter-arguments were addressed. Under the heading "Implementation", the Chairs noted:

Overall, it was found that while this attribute is implemented, it is

not implemented widely. This necessarily makes this objection a weak


"Implementation" was possibly misrepresented, since recent research provides evidence of both GUI based browsers as well as authoring tools and adaptive technology software that have native implementation today for the longdesc attribute, demonstrating far wider implementation than first suggested. Alternative implementations/support also include Universal Feed Parser by Mark Pilgrim and Sam Ruby's Planet Venus.

Recent Research on Assistive Technology

Recent research finds that modern screen readers have good support of the longdesc attribute. They typically announce the presence of a long description when available, and provide users with the option of reading it by executing a specified keystroke. Support includes:

NVDA in combination with Firefox has partial longdesc support. A user can access longdesc for non-linked, non-clickable images by pressing enter on the image. This was recently upgraded to provide complete support for NVDA users.

Recent Research on Browsers

Recent research finds that longdesc has been implemented as follows:

  • Opera, Firefox, Chromium, and Internet Explorer all support longdesc DOM reflection.
  • Opera (native support) - exposition of the longdesc is exposed by a right click on the image for which the longdesc has been defined.
    • TellMeMore Opera extension - Respects a web page's visual design yet provides critical functionality. It will "Find things that have more description available, and show them on demand. Where images (or something else) have a longdesc attribute, the extension notifies by changing its icon and title, and enables the user to see a list of the descriptions available, in its popup. When the user selects an item in the popup, a new window opens with the description in it."
  • iCab has native support for longdesc - It not only provides the user a image context menu that activates the link to the long description, it changes the mouse cursor icon when encountering a longdesc.
  • FireFox - has accessibility API support and partial native support via the image context menu, which displays the URI of the longdesc attribute
    • Longdesc Firefox Extension by Patrick H. Lauke - adds a "View Image Longdesc" option to the image context menu that activates the link to the long description (over 24,000 downloads)
    • Longdesk 0.1 FireFox Extension by Anthony Ricaud - adds a link to the longdesc under images that provides one.
  • Long Description Favelet - This favelet "announces the number of images with longdesc attributes and provides links to the long description file in each case." Works ubiquitously in Chrome, FireFox, Internet Explorer, Safari, Opera, and iCab. by James W. Thatcher.
  • Internet Explorer
    • When used together with assistive technology like Jaws, IE makes longdesc accessible to the AT user.
    • Configuring Internet Explorer to Handle Longdesc - Adds a context menu entry to extract the longdesc attribute value and have the page navigate to its content for sighted users. by Sean Hayes.
    • Longdesc Linker for Internet Explorer 6 - Browser Helper Object (BHO) which adds a "Long Description" item to the context menu that IE uses for images
  • Netscape 7.0 (rv:1.0.1 Gecko/20020823) supports the longdesc attribute with the URL linkified.
  • Home Page Reader has native support of longdesc and is still used in Japan for longdesc, even though it stopped being maintained five years ago.

Browser Discoverability of longdesc

Innovative browser vendors and developers provide ways that make longdesc discoverable to sighted users. These include:

Recent Research on Authoring Tools

From WYSIWYG editors to content management systems recent research finds that many authoring tools support longdesc. Among them are:

Other Tools Supporting Longdesc

Providing functionality natively allows for its use within syndication feeds and other contexts in which HTML is stripped of its associated styles and scripts. Recent research has found alternative implementations/support of longdesc: