  We compute the orbital magnetization in real materials by evaluating a
recently discovered formula for periodic systems, within density functional
theory. We obtain improved values of the orbital magnetization in the
ferromagnetic metals Fe, Co, and Ni, by taking into account the contribution of
the interstitial regions neglected so far in literature. We also use the
orbital magnetization to compute the EPR $g$-tensor in molecules and solids.
The present approach reproduces the $g$-tensor obtained by linear response
(LR), when the spin-orbit can be treated as a perturbation. However, it can
also be applied to radicals and defects with an orbital-degenerate ground-state
or containing heavy atoms, that can not be properly described by LR.
