The goal for this website is to promote the long-term health of the Web. One of the most important factors defining the health of the Web is how open and accessible the information is. This is why standards, proper document formation, and semantic markup are so important.
In an ideal world, all user agents in use would be fully up-to-date, supporting all of the most recent Web standards. Unfortunately, that isn’t real life. A fairly large percentage of the world’s population still uses less-than-current web browser versions, and most the world’s population uses Internet Explorer, with the worst overall support for Web standards of any major brand.
Graceful degradation only goes so far, especially when you start getting into the blossoming world of XML. The big question is, at what point do we decide it’s unreasonable to support older, outdated browsers? How much of our document’s efficiency and semantic accuracy are we willing to sacrifice in order to cater to older user agents? And, more importantly for the purpose of this website, what effects do these decisions have on the long-term health of the Web?
I think we can all agree that, as far as the Web goes, it’s unhealthy for people to be using outdated web browsers. I think we can also agree that it’s unhealthy for developers of popular web browser brands to halt development for several years. We can’t actually force people to update their computers or browser developers to improve their browsers, but wouldn’t you agree that it’s unhealthy to directly reduce incentive for these actions to take place?
The original question is still the same: at what point do we decide it’s unreasonable to support older, outdated browsers? A growing sentiment is that it’s unreasonable to support Internet Explorer 5.5. Where money and necessary services aren’t involved, a few even argue that it’s unreasonable to support Internet Explorer 6 and that users should be made aware that their browser version is five years old and should therefore expect their browser to fail at newer documents. That’s certainly a bit extreme for most types of websites, but it’s a push that, as we have learned over the last half decade, is needed to some extent if we hope for the situation to become more pleasant.
The answer to the question is rather subjective, and it depends on the content of your website. The owner of a small personal weblog could more easily ignore Internet Explorer 5.5 than a business website could, and the negative end of the trade-off would be much less significant. As you will see, when discussing complex ideas like the overall health of the Web, the answers will rarely be black and white.