How Does IE 8 Behave?
"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."
"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."