run X program headless in Linux

On remote server:
1. run "xvfb-run xterm" (replace xterm with your program). The runs a virtual frame-buffer/X server. The default display is :99. You can change that.
2. find out where the X auth file is written. Default iat /tmp/xvfb-run.XXXX/Xauthority.
3. x11vnc -display :99 -nopw -auth /tmp/xvfb-run.o3K0jQ/Xauthority

 on your local desktop, run vnc viewer to connect to the remote server. You can set up password in the server if you want to.