What is the best way to get multiple instances of a program to share information?
<p>There's information my program has to send from one part to another, such as from <code>DragEnter</code> to <code>GiveFeedback</code> to change the cursor. This is easily done with a variable as a flag. However – what if the user starts several instances of the program?</p>

<p>One way would be to write information to a file, but it seems best to do as little disk operations as possible. Another way would be to use pipes, but it seems a bit complicated if there are many instances of the program. Is there another way?</p>
