As a web developer / designer, I have to deal with writing code that works on many different web browsers. This can cause a lot of extra work that is usually not worth the trouble.
Specifically speaking of Internet Explorer 6, which came out in 2001, has been one of the worst / hardest browsers to design for.
Most browsers follow W3 standards. Microsoft’s Internet Explorer is notorious for not following standards, thus rendering broken pages and not supporting cutting edge features.
With this being said, Microsoft has actually developed a decent browser, finally following standards with IE 9.
So of the most important new CSS (Cascading Style Sheets) features are drop shadows, rounded corners and transparency, which gives designers more freedom from having to use Photoshop for these effects. IE is finally support these effects.
Below are some good IE resources-