Differences of the many Linux's

It is worth it to note the difference between "Linux" and a "Linux distrobution". It's a bit pedantic to use the old RMS line that it is really "GNU/Linux" (which is debatable) to illustrate that Linux is the kernel of the OS; Linux is not an OS on its own. All those you listed are Linux distros, as they include many packages of software that create a fully functioning OS. Each one uses a different set of packages and may also use a different/custom packaging manager. They also differ on how the entire system is laid out and administrated. The largest sets of distros are split between the RPM system (Redhat/Fedora/Yellowdog), the Debian apt system (Debian/Ubuntu/MEPIS), and the Gentoo emerge system. Other, more hardcore, systems are based on Slackware. For a new user I'd suggest starting with something like Ubuntu. It's fairly well organized mature enough to run "out of the box" on most recent PC hardware (ie, 5-8 years old or so).

There are many different things to consider in an operating system. I don't know all of the differences. Are you looking at differences in ease-of-use/installation, performance, GUI (ie. KDE vs. Gnome vs. both vs. neither), shell command differences, shell differences, Terminal program differences, platform availability, drivers, different server software like web / email / database, etc and so on ad infinitem ...

Red Hat
I think this was the first linux distribution to provide a really easy installation package. Many other distributions (ie. Ubuntu, Gentoo) now provide installers that take the pain out of installing linux. Red Hat also provides "solutions" for larger customers, and at the same time they provide their "free" (beer and libre) distribution of linux.

Fedora
I don't know much about this one. Hey there are lots of distributions, maybe this is a good one.

Ubuntu
This is currently a very popular distribution. I installed it on my iBook 500Mhz G3. There were a few problems, but it was easy to install and use.

Gentoo
Again, I don't know much about this one. It seems popular.

Yellow Dog
This is a linux that was made to run on Macs.

I would also include Debian and [b]Slackware[\b]
And, don't forget BSD. In Mac OS X, [b]Darwin[\b] was derived from [b]FreeBSD[\b].

Fedora is the public free (beer/libre) community version of Red Hat Enterprise Linux (RHEL). Red Hat founded Fedora to create a more community oriented distribution and to remove the "corporate oversight" that shadowed the older Red Hat releases. Yellow Dog is derived from Red Hat. Mepis and Linux Mint are derived from Ubuntu which is derived from Debian. Sabayon is derived from Gentoo. Somewhere there is a UNIX family tree that shows what branched from what and who got merged with who.

There is a Linux distro for just about every need. The first thing to do is to decide what is to be done with the system, then pick a distro to fit.

Found it. http://730x.up.md/wp-content/44218-1.png

I've found Fedora to be a very nice system. I would suggest it if you're using it on a newer system, but anything slower than 1.5-2GHz it's painful on. Ubuntu seems to be a decent system also, and much better for slower systems. The last time I tried Sabayon, I had bad luck with getting it to boot.

http://www.polishlinux.org/choose/comparison/

I found this helpful (though I was actually using it to choose a version of BSD, it covers many aspects of the linuxen).

How easy is it to get a new world PPC mac to dual boot OS X and, say, fedora?

I set up a dual boot around 2003 on a powercomputing clone, and I don't think it was too hard, but it didn't work too great, I was using LinuxPPC, and I also tried MkLinux, which worked a bit better, but neither worth keeping. I have a feeling things will have probably gotten better since then, though. ... (looks for documentation) http://lowendmac.com/meta/2k1214.html

Yeah, all you have to do is set up the partitions (a complete rewrite of the disk with fdisk, if you're using one disk), for the most part, then tell the boot manager... BootX, or lilo, can't remember, that there's another boot partition other than the Linux install (I believe they have a tool just for this, or you can edit a text file that the boot manager uses). I think the toughest thing I dealt with was configuring the monitor I had, which will probably have improved in a more recent release than what I was using, with the hardware detection. Basically it boils down to knowing what your monitor handles as far as scan rates and resolution, then knowing how to put it into the configuration file, if the auto setup doesn't do it right (you'll have to find where the file is, I can't remember). I never had any trouble getting the standard shell/terminal mode to work, just the X.

The boot/install process is very different on PPC than on a PC. The main boot loader for NewWorld is called YaBoot (Yet Another Bootloader), it can dual boot and it most likely needs its own small partition. Recent versions of GPartEd (within the last 2-3 years) can resize an HFS+ partition, so long as one has turned off journaling from an OS X Terminal first or from Disk Utility if it's not the current boot drive (IIRC). X setup is pretty much automatic for both PC and PPC anymore. Ubuntu has dropped PPC as an "official" arch, but they still release for it. Plus, it works fairly well.

Some of the largest problems with Linux on PPC is the lack of "modern" things, like an official port of the Adobe Flash player. Other things like ATI and nVidia provided accelerated drivers are available, but the community open source version for the older ATI chips work fine on my old G3 iBook.