You would have to set up some sort of polling solution where the client that should have the object move on is constantly requesting information from the server on where the mouse position is. The server would probably need to buffer mouse movements from the first client to pass to the second client upon request. There are a few polling/streaming techniques out there and you should probably start off with googleing for "javascript streaming" or "javascript polling techniques" or "javascript comet". http://en.wikipedia.org/wiki/Comet_(programming)