火狐浏览器：
background:-moz-linear-gradient(top, red, rgba(0, 0, 255, 0.5));
谷歌：
.l6{background: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#FF0000), to(#F9F900)); } 谷歌10+
.l7{background: -webkit-gradient(linear, left top, right top, color-stop(0%,#30c6e0), color-stop(100%,#1e77db));} 谷歌1-9
不带前缀：
.l1{background: linear-gradient(to bottom, blue 2%, white 50%, orange);}
.l2{background: linear-gradient(to bottom right, blue 2%, white 50%, orange);}
.l3{background: linear-gradient(20deg, blue 2%, white 50%, orange);}
多个背景
.l5{background:url(http://pinqu.qiniudn.com/sq_daas_c5caf34a66473182975d1595c623a037) no-repeat 0 0/100% 100%;}
.l4{background: linear-gradient(to right, rgba(255,255,255,0), rgba(255,255,255,1)), url(http://pinqu.qiniudn.com/sq_daas_c5caf34a66473182975d1595c623a037) no-repeat 0 0/100% 100%;}
参考来源：http://www.cnblogs.com/lhb25/archive/2013/01/30/css3-linear-gradient.html