Acid2, Acid3, and the power of default

The test, published by the Web Standards Project, has been a tremendous success in weeding out browser bugs that stop Web designers from reaching pixel perfection in their pages. Safari and Opera ship Acid2-compliant versions, and the upcoming Firefox 3 will also pass the test.

Recently, Microsoft announced that Internet Explorer version 8 can render Acid2, and it showed a screenshot to back the claim. The news was received with joy and excitement in the Web-authoring community.

Finally, it seems, Microsoft has decided to take Web standards seriously. Designers will no longer have to spend countless hours trying to get their pages to look right in Internet Explorer while adhering to standards. Unfortunately, I think that the celebration is premature. I predict that IE 8 will not pass Acid2, after all.

But first, a few words about the next Acid test, soon to be published by the Web Standards Project: Acid3.

Acid3 will follow in the footsteps of Acid1 and Acid2; it's a tough one-page test that displays a quirky graphic when rendered correctly. No browser will pass the test at the time of its release. All vendors are equally challenged.

Whereas Acid2 was a static Web page, Acid3 will be a dynamic Web application. When browsers are improved to pass Acid3, it will become easier to write Web applications that work interoperably across browsers.

Acid3 is written for and by the Web community. Ian Hickson is the editor of the test. While he has a unique ability to write test cases that expose bugs in all browsers, he has also asked for help from others. Code contributions are welcome.

Acid2 and Acid3 both state that they should be tested using the default settings of the browser. Web usability consultant Jakob Nielsen has discussed

Opera CTO：IE 8最终可能通不过Acid2的测试

“看起来微软终于决心要严格遵从Web标准了，开发者再也不用花费数不清的时间来使他们的网页能够良好地展现在Internet Explorer上。然而不幸的是，我认为为此庆祝还为时太早。”

Opera CTO近日在CNET发表了一篇自己执笔的文章，这是其中的一段话。文章中分析了Acid2和Acid3的一些标准，并表示IE 8最终可能不会通过Acid2的测试。以下为他在文中的一些摘要：

两年前Acid2测试发布，它由Web Standards Project发布，它成功扫除了阻碍开发者获取网页完美像素的bug。Safari和Opera都已经推出了遵从Acid2的版本，即将发布的Firefox 3也将通过测试。

之前微软宣布IE8通过Acid2测试时，在Web开发社区引发了激烈回应，微软似乎想严格遵守标准，这样设计师就无需为了网页在Internet Explorer上正确表达花费过多时间。然而我认为为此庆祝还为时太早，我预测IE 8最终不会通过Acid2的测试。

无论是Acid2还是Acid3，都应该是在浏览器默认设置下测试，因为人们更多的是使用默认浏览器，保存文档也会在默认浏览器的格式下。我怀疑IE 8通过迂回的方法来支持标准。

我认为微软正在考虑三种可能的假设，我们也以此来分析每种情况：

一种假设情况是，微软要求用户“选择”支持标准。比如，为了能够正确地适应Acid2，要求用户修改IE 8默认设置。这种做法不符合测试的准则，所以这种情况下IE 8不会通过Acid2测试。

第二种假设是微软可能要求网页设定一个标记，以改变默认设置使得网页最终能够正确渲染。现在的浏览器都支持文档类型选择（doctype switch），但微软对此没有表示，只是称将支持另一种模式。如果微软支持另一种模式，Acid2测试和其他浏览器都将无法支持doctype switch。

第三种假设是将Acid2的Web地址强制编码从而融入IE 8，这种方式对网页进行特殊处理使得看起来像是通过了测试。很明显这违背了测试的精神，自然不能保证通过测试。