Answer by Walter Rumsby for Cross-Browser CSS3 Rule

Compass provides Sass mixins for many CSS3 properties meaning you can write something like:

.foo {    @include border-radius(4px, 4px);}

which will generate the following CSS:

.foo {    -webkit-border-radius: 4px 4px;    -moz-border-radius: 4px / 4px;    -o-border-radius: 4px / 4px;    -ms-border-radius: 4px / 4px;    -khtml-border-radius: 4px / 4px;    border-radius: 4px / 4px;}

This is great because you have to write less code, but it provides rules that target a wide range of browsers.