Fading Hyperlink Transition on premiumpixels.com - How?

Hover over most any hyperlink on the site (loo开发者_运维百科k at the footer on the homepage for a quick example) and you'll see a gentle fade to the hyperlink's hover color.

I was certain it was jQuery until I could find no mention of these animations in the jquery.custom.js file -- only adding specific hover color classes.

Baffled!

Looks like this is doing it:

a { 
text-decoration: none; 
color: #2c2d31;
font-weight: bold;
transition: color 0.1s linear;
-moz-transition: color 0.1s linear;
-webkit-transition: color 0.1s linear;
-o-transition: color 0.1s linear;
}

I'm embarrassed to say that I'm unfamiliar with the transition property, but I was baffled at first too, especially after I disabled javascript :)

It worked for me in FF4 and Chrome, but according to this article I quickly googled, IE9 will not be supporting this property. I wouldn't take that as fact, that's just what I found with 5 minutes research.