.xsession
From FreeBSDwiki
.xsession is a home folder script to start a window manager from a display manager. This file can be linked to .xinitrc for convenience since their configurations are identical. The only other difference between these two files is that .xsession must be executable.
Example of file content:
exec jwm
Changing permission setting (this sets for user and group):
# chmod ug+x .xsession
For all users:
# chmod +x .xsession
Linking .xsession to .xinitrc:
ln -s .xsession .xinitrc