One of the two continuations of RedHat 9 after it split into RHEL and Fedora Core in 2003.
Fedora Core is a completely FOSS GNU/Linux distro that uses RPM, Yum and a modified Linux and is financially supported by RedHat, Inc. Fedora has a very fast release cycle, producing two or three stable releases a year. As of version 3, all of Fedora Core is rather big, taking up four CDs and a little less than seven GB of hard drive space, although not nearly that much is needed to get a Fedora system up and running. Also as of version 3, the default desktop environment is GNOME but included in the nearly seven GB is also KDE and Xfce.
As of the Fedora Core 4 tests, Fedora is for the x86, x64 and PPC CPU architectures.
The only OSs on my hard drive are different versions of Fedora Core :)
Prices shown in USD.