  In this paper we study vector-valued almost minimizers of the energy
functional $$
  \int_D\left(|\nabla\mathbf{u}|^2+2|\mathbf{u}|\right)\,dx .
  $$ We establish the regularity for both minimizers and the "regular" part of
the free boundary. The analysis of the free boundary is based on Weiss-type
monotonicity formula and the epiperimetric inequality for the energy
minimizers.
