Gnome: how to globally set environment variables?

[furufuru@ccsr.u-tokyo.ac.jp]

Hello all,

I'm totally at a loss.  Could someone tell me how one should set
environment variables at the startup of Gnome?  I'm not talking about
~/.bashrc or its friends.  Since env. vars. are inherited from parents
by children, you should need to set them only at the ultimate ancestor.

Before moving to Gnome, I used xdm (a login manager), which sources
~/.xsession, so that you set env. vars. in there and you invoke
whatever program you like from there.  The latter functionality can be
replaced with Gnome's session manager (I may not be remembering the
name correctly) where you can specify programs to be invoked at the
startup.  But, what about the env. vars.?

I feel like being dumb.:-(  In the traditional Unix/Linux world,
such information used to be invaribly found in manpages.  "man gnome",
however, tells you nothing.  Where can I find information on the
startup sequence of the gnome system?  I guess gdm invokes "something"
and that "something" acts as the "ultimate ancestor".  Why is it so
hard to find such a documentation?

Regards,
Ryo
-------------
PS. I've just realized something interesting.  Programs directly
invoked from the Gnome menu or desktop seem to have init (pid 1)
as their parent.  That means the Gnome "ultimate ancestor" orphans
every child. . . .  Why does it do that?  I'm just interested.