CSS3 cross browser linear gradient

background-image:     -ms-linear-gradient(right, #0c93C0, #FFF); 
background-image:      -o-linear-gradient(right, #0c93C0, #FFF);

All experimental CSS properties are getting a prefix:

• -webkit- for Webkit browsers (chrome, Safari)
• -moz- for FireFox
• -o- for Opera
• -ms- for Internet Explorer
• no prefix for an implementation which is in full accordance with the specification.

Use top right instead of right, if you want a different angle. Use left or right if you want a horizontal gradient.

See also:

• MDN: linear-gradient

Internet Explorer

For <IE10, you will have to use:

/*IE7-*/ filter: progid:DXImageTransform.Microsoft.Gradient(startColorStr='#0c93c0', endColorStr='#FFFFFF', GradientType=0);
/*IE8+*/ -ms-filter: "progid:DXImageTransform.Microsoft.Gradient(startColorStr='#0c93c0', endColorStr='#FFFFFF', GradientType=0)";

filter works for IE6, IE7 (and IE8), while IE8 recommends the -ms-filter (the value has to be quoted) instead of filter. A more detailled documentation for Microsoft.Gradient can be found at: http://msdn.microsoft.com/en-us/library/ms532997(v=vs.85).aspx

-ms-filter syntax

Since you're a fan of IE, I will explain the -ms-filter syntax:

-ms-filter: progid:DXImageTransform.Microsoft.Gradient(
     startColorStr='#0c93c0', /*Start color*/
     endColorStr='#FFFFFF',   /*End color*/
     GradientType=0           /*0=Vertical, 1=Horizontal gradient*/
);

Instead of using a RGB HEX color, you can also use a ARGB color format. A means alpha, FF means opaque, while 00 means transparent. The GradientType part is optional, the whole expression is case-insensitive.

Here an example, which works with Opera, Internet Explorer and many other web browsers. If a browser does not support gradients, it will show a normal background color.

background: #f2f5f6;
background: -moz-linear-gradient(top, #f2f5f6 0%, #e3eaed 37%, #c8d7dc 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#f2f5f6), color-stop(37%,#e3eaed), color-stop(100%,#c8d7dc));
background: -webkit-linear-gradient(top, #f2f5f6 0%,#e3eaed 37%,#c8d7dc 100%);
background: -o-linear-gradient(top, #f2f5f6 0%,#e3eaed 37%,#c8d7dc 100%);
background: -ms-linear-gradient(top, #f2f5f6 0%,#e3eaed 37%,#c8d7dc 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#f2f5f6', endColorstr='#c8d7dc',GradientType=0 );
background: linear-gradient(top, #f2f5f6 0%,#e3eaed 37%,#c8d7dc 100%);

I've stolen this from this website. Microsoft has built their own generator here.

Rob W's answer is comprehensive, at the same time verbose. Therefore I'd like to go for a summary supporting current browsers end of 2014, while ensuring some backwards-compatibility at the same time, leaving out just IE6/7's invalid capability of rendering a linear gradient and early Webkit (Chrome1-9, Saf4-5 special way (-webkit-gradient( linear, left top, left bottom, color-stop( 0, #0C93C0 ), color-stop( 100%, #FFF ) );)

Standards syntax has changed from beginning gradient position to to direction, e.g. background-image: linear-gradient( to bottom, #0C93C0, #FFF );

Widely-supported, easy-to-read CSS:

background-color: #8BCCE1;                                             /* fallback color (eg. the gradient center color), if gradients not supported; you could also work with an gradient image, but mind the extra HTTP-Request for older browsers */
-ms-filter: "progid:DXImageTransform.Microsoft.gradient( startColorStr=#0C93C0, EndColorStr=#FFFFFF )"; /* IE8-9, ColorZilla Ultimate CSS Gradient Generator uses SVG bg image for IE9 */

background-image: -webkit-linear-gradient(       top, #0C93C0, #FFF ); /* Chrome10-25, Saf5.1-Saf6, iOS -6.1, Android -4.3 */
background-image:    -moz-linear-gradient(       top, #0C93C0, #FFF ); /* Fx3.6-15 */
background-image:      -o-linear-gradient(       top, #0C93C0, #FFF ); /* Op11.10-12.02 */
background-image:         linear-gradient( to bottom, #0C93C0, #FFF ); /* W3C, Fx16+, Chrome26+, IE10+, Op12.10+, Saf6.1+ */

An interesting side fact is, that most blog posts and browser gradient tools on the web, like f.e. famous ColorZilla's "Ultimate CSS Gradient Generator" include the MS vendor-prefixed -ms-linear-gradient value.
It's supported from Internet Explorer 10 Consumer Preview on. But when you're including standards value linear-gradient, Internet Explorer 10 Release Preview renders it appropriately.
So by including -ms-linear-gradient and standards way, with -ms you're actually addressing just IE10 Consumer Preview, which comes down to nobody in your audience.

Have you tried Colorzilla's Ultimate CSS Gradient Generator?

i got the solution for almost everything!

/* Safari 4+, Chrome 1-9 */                         background-image:   -webkit-gradient(linear, 0% 0%, 0% 100%, from(#000000), to(#FFFFFF));
/* Safari 5.1+, Mobile Safari, Chrome 10+ */    background-image:   -webkit-linear-gradient(top, #000000, #FFFFFF);
/* Firefox 3.6+ */                                      background-image:   -moz-linear-gradient(top, #000000, #FFFFFF);
/* IE 7-*/                                                  filter:                 progid:DXImageTransform.Microsoft.Gradient(startColorStr='#000000', endColorStr='#FFFFFF', GradientType=0);
/* IE 8+*/                                                  -ms-filter:             "progid:DXImageTransform.Microsoft.Gradient(startColorStr='#000000', endColorStr='#FFFFFF', GradientType=0)";
/* IE 10+ */                                                background-image:   -ms-linear-gradient(top, #000000, #FFFFFF);
/* Opera 11.10+ */                                      background-image:   -o-linear-gradient(top, #000000, #FFFFFF);
/* fallback image                                       background-image:   url(images/fallback-gradient.png);*/
/* fallback/image non-cover color */                background-color:   #000000;

Hope this might help some people :).