Xnotify is an X program which opens up connections to multiple displays and pops up a window with user input as the text. You could think of it as putting a note on the screen of as many people as you want. This allows you to let several people know something simultaneously. Additionally, on your terminal, it pops up a window with a list of all of the connections and whether they have been acknowledged. When someone acknowledges the message, his/her response or simple acknowledgement is given in the response window. When all connections are acknowledged, you can dismiss this response window.