  Modelling long-time convective flows in the interiors of stars is extremely
challenging using conventional compressible hydrodynamics codes due to the
acoustic timestep limitation. Many of these flows are in the low Mach number
regime, which allows us to exploit the relationship between acoustic and
advective time scales to develop a more computationally efficient approach.
MAESTROeX is an open source low Mach number stellar hydrodynamics code that
allows much larger timesteps to be taken, therefore enabling systems to be
modelled for much longer periods of time. This is particularly important for
the problem of convection in the cores of rotating massive stars prior to core
collapse. To fully capture the dynamics, it is necessary to model these systems
in three dimensions at high resolution over many rotational periods. We present
an overview of MAESTROeX's current capabilities, describe ongoing work to
incorporate the effects of rotation and discuss how we are optimising the code
to run on GPUs.
