This is a preview of the next major version of Yum. It does package management using RPM, libsolv and hawkey libraries. For metadata handling and package downloads it utilizes librepo. To process and effectively handle the comps data we have libcomps.
DNF and all its dependencies are available in Fedora 18 and later, including the rawhide Fedora. You can install DNF from the distribution repositories there:
sudo yum install dnfIn other RPM-based distributions you need to build all the components from their sources.
The DNF package contains man pages, dnf(8) and dnf.conf(8). It is also possible to read the DNF documentation from your browser. There's also a wiki meant for contributors to DNF and related projects.
Please report any bugs to the Red Hat bugzilla, make sure to check the issue has not been fixed in a later version. Freenode's irc channel #yum is meant for discussions related to both Yum and DNF.