standard feedback button in many sites?

I noticed that many website have a nice 'feedback' button in their page. It usually appear on开发者_如何学运维 the left side and it is displayed vertically 'f e e d b a c k' .

see http://www.protectedplanet.net/ for an example.

I would like to know (Because I could not figure that out) if this is achieved just by a css transformation , javascript (and if so how to do it) or if it just a gif/jpg ?

Thanks

p.s. Rather than guessing can people explain how exactly it works. For example if people says it's an image where is it ?

It usually is a background image (for compatibility with older browsers). Some text is also present in the markup, but positioned outside the view-port.

The site you supplied as example uses an image and the feedback functionality is a widget:

a#uservoice-feedback-tab {
    background-color: #FF6600;
    background-image: url("http://cdn.uservoice.com/images/widgets/en/feedback_tab_white.png");
}

It's an image, because only the newest browsers support CSS 2D transforms. Although in theory, you could use 2D transforms and add support for IE8- by using the proprietary DXImage filters. But then, you couldn't get support for other older browsers without equivalent support (Safari 2, Firefox 2.0, Opera 9, etc.).