让IE 6-9 支持 CSS3 | 让旧版本 IE 支持 CSS3

PIE makes Internet Explorer 6-9 capable of rendering several of the most useful CSS3 decoration features.
http://css3pie.com/

**Supported CSS3 Features**

• border-radius

• box-shadow

• border-image

• CSS3 Backgrounds (-pie-background)

• Gradients

• RGBA Color Values

• PIE Custom Properties

• -pie-watch-ancestors

• PNG alpha transparency and -pie-png-fix

• Lazy Initialization (-pie-lazy-init)

• Layout polling (-pie-poll)

• :hover tracking (-pie-track-hover)

• :active tracking (-pie-track-active)