A popular GNU-Linux distribution with the GNOME desktop environment. Partnered up with Canonical, Ubuntu is a really good operating system for your computer/laptop/netbook/tablet.
Person 1: Hey! I just got Ubuntu Linux!
Person 2: Woah, that looks really ninja, like totally man!
Person 1: Yeah, I guess
Person 2: How much is that?
Person 1: Oh, it's free.
Person 2: WTF.