A text shows up smoothly when hovering thumbnails. Is this a jQuery plugin or just CSS?

Question

I don't know the exact words to describe this behavior in the following pages: http://kyanmedia.com/ and http://www.jayhollywood.com.au/. When you hover the pictures (thumbnails). A text shows up smoothly. Is this a jquery plugin or just CSS?

How to reproduce that behavior/effect?

Answer 1

Check it out on CSS-tricks:

http://css-tricks.com/examples/GarageDoorMenu.zip

and

http://css-tricks.com/examples/GarageDoorMenu/

Edit:

It uses two DIV's placed on top of each other. Then when you hover, it will animate the background-position property of the "garage-door" div. The garage-door is transparent below it's "door" graphics, such that you can view the layer below.
This particular implementation uses JQuery:

$(".link").hover(function(){
    $(this).parent().stop()
        .animate({backgroundPosition: '(0px -100px)'}, 500 );
}, function() {
    $(this).parent().stop()
        .animate({backgroundPosition: '(0px 0px)'}, 500 );
});