Yep it is... you will find it should work perfectly fine in all the latest versions of Mozilla Firefox, Apple Safari, Google Chrome and Opera! It's just Internet Explorer that won't have the support for it (and of course people with older versions of the other products). Well worth giving it some consideration!
I am very happy to see this finally being widely catered for. Of course, Microsoft are taking their time.
I do use these styles for small elements, but I stick to rounded graphics for something which *must* be rounded - as in it would look totally out of place with the rest of the design if not.
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