Microsoft's development direction of Internet Explorer 9 is unambiguous: implementing HTML5 Web standards is the name of the game, with the intent of letting developers use the "same markup" to work everywhere. As IE General Manager Dean Hachamovitch said at MIX10 this week, "We love HTML5 so much we actually want it to work."
Redmond is targeting real-world applications based on real-world data. For example, every single JavaScript and DOM API used by the top 7,000 websites was recorded. IE9 will deliver support for every API used by those sites.
I have seen that Safari 4 beta passes the acid3 test with 100/100
The Acid3 Test
Does anyone know how relevant this test is to the performance of a browser? and should we be looking at this with a grain of salt?