Fedora ships a kernel with proprietary firmware. That is the only freedom
problem I am aware of. It can be solved by installing the Linux-libre kernel
(used by every 100% free GNU/Linux distribution). Fedora is a lot concerned
about patent lawsuits. We can understand that, especially because most of its
developers live in the USA (whereas Trisquel developers are in the EU where
software patents are illegal). As a consequence, Fedora does not propose free
codecs to read/write patented formats (contrary to Trisquel that has them in
the default install). Because almost all users want to play their MP3 songs
and their MP4 videos, they end up adding a popular third-party repository
that contains the required codecs... and much proprietary software. That is
why, in practice, Fedora boxes usually are far from being "pure" (I reuse
your word).
Gentoo that is listed as well on https://prism-break.org is far worse: the
default configuration let the user install any proprietary software from the
primary installation system (Portage). She has to explicitly state (by adding
a keyword to a variable specifying the accepted licenses + another keyword to
the USE variable to get a deblobbed kernel) that she only wants free
software.
I totally agree that the first choice of an OS that PRSM-break should
recommend is Trisquel. In addition to the label "approved by the FSF",
Trisquel deserves both the "stable" label and the "user-friendly" label. No
need to hesitate mabra: go for Trisquel! :-)
