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Accessibility Features in Firefox 编辑

Assistive Technology Support on Windows

"I am a full Firefox convert with the release of 1.5. At my next opportunity, I intend to convert my family over to it too."
Darren Paskell, from Window-Eyes beta testing list

Firefox works with popular screen readers, with the best support currently coming from GW Micro's Window-Eyes 5.5. We are optimistic that JAWS support will catch up this year. In recent articles from both AFB's Access World and NFB's Voice of the Nation's Blind, reviewers found no significant roadblocks in moving to Firefox from Internet Explorer for screen reader users. In fact, the same keyboard commands are still available, so users can become comfortable and productive right away.

Screen magnifier users can also benefit from Firefox's powerful features today, as caret and focus tracking are fully enabled. Mozilla Corporation is currently reaching out to work with AI Squared, the makers of ZoomText, in order to enable complete support of advanced ZoomText features such as the Doc Reader and App Reader. We are also optimistic that the the makers of MAGic and Lunar/Supernova will add Firefox support in the coming year.

Mozilla has support for Dragon Naturally Speaking. Some users of the professional version are happily playing with Dragon and Firefox. We are optimistic that Nuance will work to improve access to the user interface in the coming year.

Firefox on Linux currently boasts the best onscreen keyboard support in the industry via GOK, the Gnome Onscreen Keyboard. Basic screen reader accessibility is available via the Fire Vox extension. Fire Vox can also be used on Windows or OS X.

For more detailed information, please check the assistive technology compatibility guide is kept on an editable Wiki.

Keyboard Support

"Mozilla Firefox is a web-browser with superior keyboard support."
Alan Cantor, Cantor Access Consulting

Firefox includes keyboard access to all of its amazing features:

Browse with caret allows users to select arbitrary content with the keyboard and move through content as if inside a read-only editor. This allows copying arbitrary pieces of text to the clipboard. The F7 key toggles this feature on/off.
Tabbed browsing helps keyboard users by putting all of the browsed documents in one Firefox application window rather than cluttering the Alt+Tab order which makes keyboard navigation within the entire Windows OS much simpler.
Both history and bookmarks can be searched with a "quick search" field that quickly narrows the list down via a substring search.
Bookmarks can have a keyword assigned to them which can be typed into the address bar to bring up the bookmark. A "smart keywords" feature enhances this even further by allowing custom searches from the command line such as "word punditry" to look up the word "punditry" in an online dictionary. These smart keywords can be setup via the context menu for the search field on the desired website.
Integrated web search via Ctrl+K is much faster to use than first going to the search tool's web site. Custom searches can be added to this quick search bar and the user can switch between them by choosing from a drop down available via the standard Alt+down arrow key combination.
The built-in text zoom feature can be accessed with the Ctrl+plus and Ctrl+minus hotkeys.
The Accessibility Extension may be installed on top of Firefox, allowing keyboard access to document structure.
The Find Bar allows for quick navigation to links and text searching without opening a separate dialog -- this allows more convenient use by screen magnification users because there is a single point of regard for the search. It also assists users of input aids because there are far fewer keys to type to get the desired location. For example, it is possible to navigate to the desired link by pressing 2 letter keys rather than tabbing through many links to get there. Caret browsing allows you to move through web content one letter a time. You can even select web content and copy it to the clipboard. -- all with the keyboard
Detailed Advanced Javascript control: Mozilla gives you the ability to fine tune what Javascript is allowed to do while you browse. For example, you can disable functions that websites use to move or resize windows, or to remove your status bar, to disable right-click contextual menus, change the status bar text, etc. You can furthermore control javascript capabilities to remove scrollbars, toolbars or system buttons like minimize, close and maximize by editing the about:config related properties or by editing accordingly the user.js file as explained in this "Disable Other JavaScript Window Features" document.
Moving back and forward by web page (Alt+Left and Alt+Right) occurs near-instantaneously
The download manager provides keyboard access to all of your recent downloads
Operating System "Look and Feel" Support: Mozilla's default skin will match the colors and sizes currently being used in your desktop. Mozilla can follow the system appearance whether it's high or low contrast, with large or small fonts.
Text files used in configuration (techies only): configuration files are easily edited with any text editor. For example, prefs.js gives access to a large number of configuration options not available in the preferences window. Also, userContent.css allows users knowledgeable about cascading style sheets to customize the appearance of all pages that are displayed. Finally, bookmarks.html contains all your bookmarks, and is easy to move around from computer to computer.
View selection source (techies only): when you select some text and right click or press Shift+F10, you can "view selection source". This will show the HTML source for only the selected text, which is useful for understanding accessibility problems in some web sites.

Customize Your Experience!

Many users are finding the true greatness of Firefox lies in support for third party extensions. Extensions are small add-ons which can change your browser experience as you see fit. Extensions can easily be installed or removed with the extension manager in the Tools menu.

Here are some examples of accessible extensions, although there are hundreds more to try (thank you to the GW Micro knowledge base for some of this information):

Adblock Plus removes ads (and other objects, like banners) from web pages
Greasemonkey lets you add bits of Javascript ("user scripts") to any web page to change its behavior. In much the same way that user CSS lets you take control of a web page's style, user scripts let you easily control any aspect of a web page's design or interaction. We expect enterprising script writers will eventually fix annoying accessibility issues in popular web pages, and (hopefully) share their tricks with everyone!
Fire Vox extension by Charles L. Chen is a screen reader extension built just for Firefox which can read MathML

Community Contributions

The real reason behind Firefox's success is the great community of volunteers and organizations that realize they have something to benefit from a browser open to utilizing their ideas and hard work. Contributions come in many forms. The Mozilla Firefox community welcomes bug reports, ideas, documentation, answering questions in the support forums -- and nearly any kind of community involvement resulting in a browser built for a broader audience of users and developers.

Here are a couple of success stories from businesses who contributed accessibility code because they needed an accessible web browser which supported their software:

Contributes Accessible Web Applications (DHTML and AJAX)

IBM realized it needed a way to enable accessibility for ever more powerful web applications, beyond what you see on typical web pages today. Rather than go and write their own new web browser, IBM decided to trust in the openness of the Mozilla community, which accepted IBM's significant contributions. For example, IBM has delivered over 50,000 lines of code to enable accessibility in Firefox on Windows and especially for this new powerful world of "web applications". A web application may be an easier-to-use online tax assistant, a web calendar or a live sports statistics page, which is familiar in that it acts much like a desktop application. Whether the current buzzword for this technology is "DHTML", "AJAX" or "Web 2.0" doesn't really matter. This fact remains: the web is changing to become more interactive and less like a bunch of plain documents. Firefox is currently the only browser to support the newly evolving standards for making these web applications accessible. Companies such as Yahoo! have announced they are already working with the technology their new richer interfaces accessible with this new technology. Developers, please see our DHTML accessibility documentation and get involved in writing tools and websites using this new technology.

Sun Contributes Code to Improve Accessibility on UNIX

A similar story occurred at Sun Microsystems. Sun needed an accessible web browser for UNIX, specifically for Solaris. Again, rather than develop a brand new web browser, it made more sense to contribute fixes that make Firefox accessible on UNIX. Thanks to Sun's efforts we already have excellent support for the Gnome Onscreen Keyboard (GOK). Meanwhile, IBM has joined Sun's effort to make Firefox as screen reader accessible on UNIX as it is on Windows, because the same core accessibility work applies to Linux. The two companies anticipate that in 2007, Firefox will support topnotch screen reader accessibility on UNIX and Linux.

That's the great thing about the open Firefox community model and source code license -- anyone can contribute, and everyone benefits.