How do I pick one, though?
If you're asking me, I'd pick whichever one people you know are using. If you don't know anyone using Linux, see if there's a Linux User Group in your area that can recomend one. If that fails, any of the Desktop Linuxes are as good a place as any to start. I need to know the differences between each version before I can pick, or do I have to install each version in order to discover which one is right for me? :/
The difference in distributions are mainly a matter of which arbitrary programs someone else has decided you want to use, and how colorful the installer is. The central difference is whether to use Gnome or KDE and what kind of package distribution system you prefer (Debian, Redhat or Suse). For 99% of everyone the choice between which Linux to get is about as significant as which model car you want to get. But by all means try out as many as you possibly can. Contrary to what Apple try and tell you, there's no such thing as a 'one size fits all' operating system.That's the great thing about Linux. Want an all-guns-blazing Windows-like desktop environment? Get KDE or Gnome. Just want a lightweight Window Manager with just enough to get you along (and fit comfortably on an USB Flashdrive) get IceWM. Don't care? Let the Installer decide for you.
See? According to Apple themselves, it is based somewhat off of a Unix Foundation, so there you have it.
Like Noel said, it's a case of ambiguity. Just because it uses parts of the BSD, does not make it based on UNIX. If that where the case, any OS, even Windows NT could claim to be based on Unix.The Apple website is not a forum for technical discussion of the nature of operating system evolution, but a promotion tool to help them sell more Macs. Since Unix has a reputation of being secure and stable, it's no surprise that Jobs would want to emphasise that. Unix also has a reputation for being difficult and elitist - something Jobs somehow failed to mention in his sales pitch.
I'll pick for you: Slackware.
Come on Noel, be nice!