How much GNU is there in GNU/Linux?

I would expect that for debian and Fedora the percentage of 'other' would be much higher, simply because there is so much more software in the main repository (almost none of which is part of the GNU project)

I think SUSE has more packages than were considered for Ubuntu

I would be interested to see what the slackware numbers looked like. given that it's a smaller distro (and the size of the GNU components andthe kernel are pretty much fixed) the percentage would probably be a bit higher for both GNU and the kernel.

or you could look at embedded distros, and find that the GNU contribution fades significantly (they frequently use different libc and compiler options)

Ubuntu actively syncs packages with Debian. There are some diffs even in the core packages, but they are not that big. But then again, what was he checking: Ubuntu Main or Main+Universe? (I suppose that the sizes of Restricted and Multiverse are, in LOC, rather small, so they don't really matter). Main+Universe is roughly comparable to Debian's Main. I suspect (though didn't really check) that there is a higher ratio of GNU programs in the core (Ubuntu's Main) than in the peripherials.

If I'm right, you'll find a higher ration of GNU code in RHEL/Centos than in Fedora (of a "comparable generation"), and likewise in SLES compared to openSUSE (Did I get the names right?).