HTML and CSS Reference
that haven't been imagined yet and that will show up on the devices that reach the public in
2009. Whether to exclude a browser is not a choice we have to make.
Instead, we need to consider what “support” actually means. In the past, people have
taken “support” to mean “everybody gets the same thing.” If we support Internet Explorer 6
and Netscape 4, then the site will look virtually identical in both browsers—and so on. Thus,
web designers and developers learned to use a “lowest common denominator” approach,
poorest browser they'd chosen to support. But this thinking is flawed in that it offers benefits
to no one.
Nate Koechley, a Senior Web Developer at Yahoo!, gave this example on the Yahoo! Developer
Network ( http://developer.yahoo.com/yui/articles/gbs/gbs.html ):
Consider television. At the core: TV distributes information. A hand-cranked emergency
radio is capable of receiving television audio transmissions. It would be counter-
productive to prevent access to this content, even though it's a fringe experience.
Some viewers still have black-and-white televisions. Broadcasting only in black-and-
white—the “lowest common denominator” approach—ensures a shared experience but
benefits no one. Excluding the black-and-white television owners—the “you must be
this tall to ride” approach—provides no benefit either.
An appropriate support strategy allows every user to consume as much visual and inter-
active richness as their environment can support. This approach—commonly referred
to as progressive enhancement—builds a rich experience on top of an accessible core,
without compromising that core.
Broadcast television offers full color. It offers Dolby Pro Logic surround sound. It offers
high-definition resolution and clarity. If your television supports these technologies, you get
the richest TV experience possible. If it doesn't, your experience will not be enhanced—but
you will still get the core content of the television program.
This is very much the same approach the web standards movement applies to the Web.
All browsers, no matter what device they're on, how old they are, or how technologically infe-
rior they are, ought to get the core content of the page (in most cases, this means text, images,
etc.). The latest and greatest browser will get the richest experience. Everything else will be
somewhere in between.
Graded Browser Support
In February 2006, the Yahoo! Developer Network ( http://developer.yahoo.com/ ) introduced
the concept of graded browser support . This wasn't actually a new idea, but it may have been
the first time it was ever written down and presented in a palatable way to the masses, and it
also offered evidence that major Internet companies (such as Yahoo!) were thinking along