With xinit or startx

The program xinit — executed directly or by the script startx — starts the X Window server and the initial clients like the window manager. The X Window server can be specified on the command line (the default is usually X :0). With XposeXrecord the X Window server command is substituted by the xposexrecord program, which itself calls the real X Window server (X Window server) with the display number 1 (Display connection):

xinit -- /opt/XSOXposeXrecord/bin/xposexrecord serverCommand /usr/bin/X11/X :1

However, if there is a system wide file (e.g. /usr/X11R6/lib/X11/xinit/xserverrc) or if the home directory contains the executable file .xserverrc, then xinit uses this file for starting the X Window server:

# $HOME/.xserverrc
/opt/XSOXposeXrecord/bin/xposexrecord serverCommand /usr/bin/X11/X :1