How to create CSS overlapping tabs?

OSResources - How to create CSS overlapping tabs?: "Sometimes simulating a real desktop interface for your web application can be a real challenge, especially when dealing with tabs. Side-to-side tabs are not easy to create in CSS, but overlapping tabs are even harder. I had to create overlapping CSS tabs for the Interaction Ajax chat application and I thought I would share this HOW-TO with you to save you hours :)"