The Zero Clipboard library provides an easy way to copy text to the clipboard using an invisible Adobe Flash movie, and a JavaScript interface. The "Zero" signifies that the library is invisible and the user interface is left entirely up to you.
This library is fully compatible with Flash Player 10, which requires that the clipboard copy operation be initiated by a user click event inside the Flash movie. This is achieved by automatically floating the invisible movie on top of a DOM element of your choice. Standard mouse events are even propagated out to your DOM element, so you can still have rollover and mouse down effects.
