slackbuilds_ponce/system/lxsession
..
doinst.sh
lxsession.info
lxsession.SlackBuild
README
slack-desc

lxsession (LXDE session manager)

LXSession is the standard session manager used by LXDE (Lightweight X11
Desktop Environment).  A session manager is used to automatically start
a set of applications and set up a working desktop environment.

if you want to build this for gtk+2 pass to the script the switch

  GTK3=no

you will need libunique as a dependency, in this case