I am investigating if it is possible to reflect mouse movements at a client (client1) desktop to another client (client2) over the Internet.

This may be similar to PCAnywhere or VNC products where the desktop is viewed, or could be limited to a presentation application or a browser window at client1 being viewed by client2.

If possible I would also like to investigate ways of doing this without client2 having to download anything (such as an applet or a plugin).

Any useful information appreciated.