"A feature of free and open source software is that anyone can
make a copy of the software, rebrand and market it and sell it to
the world, as long as they abide by the terms of the original
license(s) under which it was distributed.
"Most, but not all, of the distributions that Distrowatch
currently lists began life as copies or derivatives of one or other
of the generic Linux distributions - Red Hat, Slackware or Debian -
each of which owed some kind of a debt to Linux pre-history in the
shape of SLS or Owen le Blanc's MCC Interim Linux, which is often
claimed to be the first installable Linux distribution.
"Red Hat owns the brand and the quality assurance that goes with
the Red Hat trademark, but does not "own" the software it sells.
For this reason CentOS and Oracle are able to provide rebranded
versions of Red Hat Enterprise Linux which provide "complete
upstream compatibility" with Red Hat's product without fear of