  We present a major upgrade of MGCAMB, a patch for the Einstein-Boltzmann
solver CAMB used for phenomenological tests of general relativity against
cosmological datasets. This new version is compatible with the latest CosmoMC
code and includes a consistent implementation of massive neutrinos and
dynamical dark energy. The code has been restructured to make it easier to
modify to fit the custom needs of specific users. To illustrate the
capabilities of the code, we present joint constraints on the modified growth,
massive neutrinos and the dark energy equation of state from the latest
cosmological observations, including the recent galaxy counts and weak lensing
measurements from the Dark Energy Survey, and find a good consistency with the
{\Lambda}CDM model.
