How Does IE 8 Behave?

As Microsoft continues to tout its push toward increased Web browser interoperability, Google releases the results of a recent run of its Sputnik JavaScript conformance test, showing Microsoft's Internet Explorer falling behind on JavaScript conformance.

As Microsoft continues to tout its push toward Web browser interoperability, Google has released the results of a recent run of its Sputnik JavaScript conformance test, which shows Microsoft's Internet Explorer falling behind on JavaScript conformance.

In a March 11 blog post, "Does Your Browser Behave?" Christian Plesner Hansen, a Google software engineer, said the company has released a test runner for Sputnik so that users can run the complete Sputnik suite of more than 5,000 tests to test the JavaScript compliance of their browsers.

"Incompatibilities between browsers remain one of the biggest challenges for Web developers," Hansen said. "We hope that giving users and browser vendors an easy way to test their browser will help promote browser robustness and compatibility across the industry."

Describing the results of a recent preliminary run of Sputnik against five prominent browsers, Hansen said:

""You can also use Sputnik to compare browser conformance. For example, below is an experimental plot that compares five popular browsers and which we hope to update as new stable versions of the browsers are released. We created this chart by running Sputnik in each of the five browsers and then plotting each browser such that the fewer tests a browser fails the closer it is to the center and the more failing tests two browsers have in common the closer they are placed to each other. In this example, when running Sputnik on a Windows machine, we saw the following results: Opera 10.50: 78 failures, Safari 4: 159 failures, Chrome 4: 218 failures, Firefox 3.6: 259 failures and Internet Explorer 8: 463 failures.""

Sputnik, which Google launched in June 2009, "touches all aspects of the JavaScript language defined in the third edition of the ECMA-262 spec," Hansen said. "In many ways it can be seen as a continuation of and a complement to existing browser conformance testing tools, such as the Acid3 test. While we are always focused on improving speed, Sputnik is not about testing how fast your browser executes JavaScript, but rather whether it does so correctly."

Moreover, Hansen added:

""When we first released the Sputnik test suite we noted that to be compatible with the web you sometimes had to be incompatible with the JavaScript spec. Since then a new version of the spec, ECMAScript 5, has been released. Besides introducing a number of new language features, ECMAScript 5 changes how many existing features are defined to bring them in line with how they are used on the web. We are updating the Sputnik tests to reflect those changes so that 0 failures would mean not only compatibility with the spec but also compatibility with the web.""

Despite the Sputnik test results showing Internet Explorer lagging behind other browsers in JavaScript compliance, Hansen gave a nod to the software giant for its efforts to continue to pursue compliance as an ultimate goal, saying:

""We are excited to see the efforts on conformance testing by other browser makers. For example, where Sputnik tests the language features in ECMAScript 5 which were also present in ECMAScript 3, Microsoft's es5conform project tests the new language features that were added in ECMAScript 5." "