  This paper reviews current experimental and theoretical progress in the study
of dipolar quantum gases of ground and meta-stable atoms with a large magnetic
moment. We emphasize the anisotropic nature of Feshbach resonances due to
coupling to fast-rotating resonant molecular states in ultracold s-wave
collisions between magnetic atoms in external magnetic fields. The dramatic
differences in the distribution of resonances of magnetic $^7$S$_3$ chromium
and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron
angular momentum is analyzed. We focus on Dysprosium and Erbium as important
experimental advances have been recently made to cool and create
quantum-degenerate gases for these atoms. Finally, we describe progress in
locating resonances in collisions of meta-stable magnetic atoms in electronic P
states with ground-state atoms, where an interplay between collisional
anisotropies and spin-orbit coupling exists.
