by Fitzcarraldo » Fri May 15, 2009 14:25
Sabayon Linux is a customised version of Gentoo Linux. It has two off-the-shelf package managers: Gentoo's Portage plus Sabayon Linux's very own Entropy. You can read all about both of them -- including the commands -- in the Sabayon Linux Wiki (see the link at the top of this page). There are various third-party GUIs for Portage, one of which is Portato. And Entropy has the Spritz GUI for those who like a GUI. Again, you can read all about it in the SL Wiki, which also has an installation tour guide.
Portage downloads source code onto your HDD and compiles it. Entropy downloads pre-compiled ('binary') packages onto your HDD. So Entropy is like the package managers for the vast majority of Linux distributions (including the two you mentioned). Binary packages may not be optimised for your specific hardware and software environment but, to be honest, in most cases you don't notice a difference.
Portage is more complicated and means that, if you do not know what you are doing, you can break your installation more easily. Entropy is simpler to use and thus more newcomer-friendly.
Both package managers allow you to keep your installation ('world') up to date: the so-called 'rolling release' system. With Entropy this is particularly easy.