Board Thread:Support Requests - Getting Technical/@comment-3032314-20130726013253/@comment-12424413-20130726015339

The box-shadow property is supported in IE9+, Firefox 4, Chrome, Opera, and Safari 5.1.1.

Not sure if this is true anymore but although box-shadow is the official property name, one must use the vendor-specific prefixes in order to use it in Webkit browsers (i.e. Chrome and Safari) as well as older versions of Firefox: