Giving a presentation with a dual screen layout on linux

When giving a presentation with a projector it is sometimes better to use a dual screen layout instead of a cloned display. If you still want a preview of the projector screen on your primary screen, you can do this:

0. Install x11vnc and a vnc viewer (e.g. xtightvncviewer).

1. Connect the projector.

2. In your system display settings, move the projector to the left or your primary screen (not strictly necessary, but I had weird clipping issues otherwise).

3. Start a vnc server for your second display with

   Copyx11vnc -clip xinerama0 -scale 0.8
   

   (or xinerama1 for the second screen etc).
   You can control zoom with the scale parameter.

4. Show the screen using vncviewer. Enter localhost as the server.

5. Get accustomed to how this behaves. Mouse movement is a bit weird, because your cursor will jump to your second monitor, as soon as you enter the vnc display.