This is just a quick overview of what has change from the vanilla portage-utils (which doesn't work with paludis nor has overlay support by the way..).
If you're not using gentoo, and paludis, then you probably have nothing to do with this.
Here are some of the nice things you can do with portage-utils
sam@truc ~ $ q --ls-overlays Overlay(s) : Name : einit location : /var/repos/einit metadata : /var/cache/metadata/einit Name : initng location : /var/repos/initng metadata : /var/empty Name : local location : /var/repos/local metadata : /var/cache/metadata/local Name : gentoo location : /var/repos/gentoo metadata : /var/repos/gentoo/metadata/cache
sam@truc ~ $ qlist --installed dev-util/ dev-util/ctags dev-util/cvs ... dev-util/subversion dev-util/unifdef dev-util/valgrind
sam@truc ~ $ qlist --installed dev-util/ -vv dev-util/ctags-5.6 dev-util/cvs-1.12.12-r4 ... dev-util/subversion-1.4.3 dev-util/unifdef-1.20 dev-util/valgrind-3.2.3
sam@truc ~ $ qsearch app-portage/ -o paludis-extras app-portage/gentoolkit Collection of administration scripts for Gentoo (Paludis) app-portage/portage-utils small and fast paludis helper tools written in C
sam@truc ~ $ qsearch -o local '' dev-lang/tcl Tool Command Language dev-lang/tk Tk Widget Set media-sound/ncmpc A ncurses client for the Music Player Daemon (MPD) svn version net-im/centerim CenterIM is a fork of CenterICQ - a ncurses ICQ/Yahoo!/AIM/IRC/MSN/Jabber/GaduGadu/RSS/LiveJournal Client # or, the following way which accept partial name for overlay (might be a little slower though) sam@truc ~ $ qsearch ::cal dev-lang/tcl Tool Command Language dev-lang/tk Tk Widget Set media-sound/ncmpc A ncurses client for the Music Player Daemon (MPD) svn version net-im/centerim CenterIM is a fork of CenterICQ - a ncurses ICQ/Yahoo!/AIM/IRC/MSN/Jabber/GaduGadu/RSS/LiveJournal Client