блин. Вы вообще доку читали? RTFM!
http://www.gentoo.org/doc/en/handboo...ap=8#doc_chap3
открываешь /etc/rc.conf и видишь:
# XSESSION is a new variable to control what window manager to start
# default with X if run with xdm, startx or xinit. The default behavior
# is to look in /etc/X11/Sessions/ and run the script in matching the
# value that XSESSION is set to. The support scripts is smart enouth to
# look in all bin directories if it cant find a match in /etc/X11/Sessions/,
# so setting it to "enligtenment" can also work. This is basically used
# as a way for the system admin to configure a default system wide WM,
# allthough it will work if the user export XSESSION in his .bash_profile, etc.
#
# NOTE: 1) this behaviour is overridden when a ~/.xinitrc exists, and startx
# is called.
# 2) even if a ~/.xsession exist, if XSESSION can be resolved, it will
# be executed rather than ~/.xsession, else KDM breaks ...
#
# Defaults depending on what you install currently include:
#
# Gnome - will start gnome-session
# kde-<version> - will start startkde (ex: kde-3.0.2)
# Xsession - will start a terminal and a few other nice apps
XSESSION="kde-3.2.1"