  A multigrid framework is described for multiphysics applications. The
framework allows one to construct, adapt, and tailor a monolithic multigrid
methodology to different linear systems coming from discretized partial
differential equations. The main idea centers on developing multigrid
components in a blocked fashion where each block corresponds to separate sets
of physical unknowns and equations within the larger discretization matrix.
Once defined, these components are ultimately assembled into a monolithic
multigrid solver for the entire system. We demonstrate the potential of the
framework by applying it to representative linear solution sub-problems arising
from resistive MHD.
