There are several other limitations by different browsers where the input focus should be on HTML input elements. Additionally, in these events, you have only access to plain text or HTML in some browsers. But this is not enough for a fully-featured word processor such as TX Text Control.
Web.TextControl implements two different clipboards: Server-side and client-side. The main clipboard is completely independent from the system clipboard. Each user gets a custom, fully featured, clipboard server-side to copy and paste formatted content inside the editor.
Additionally, formatted content can be pasted into the editor from outside using a separate input window to distinguish between the server-side and the client-side clipboard.
ZeroClipboard can be glued to a specific HTML element. Due to the browser security model, the access to the clipboard is only granted on a user action such a click. The Flash SWF movie is an invisible layer on top of the HTML element. When clicked, text can be added to the clipboard. The following animated screenshot shows the clipboard solution in action:
[TX Text Control implements ZeroClipboard. TX Text Control is on the left side and MS Word on the right.]