  Next-to-leading order (NLO) QCD predictions for the production of heavy
quarks in proton-proton collisions are presented within three different
approaches to quark mass, resummation and fragmentation effects. In particular,
new NLO and parton shower simulations with POWHEG are performed in the ALICE
kinematic regime at three different centre-of-mass energies, including scale
and parton density variations, in order to establish a reliable baseline for
future detailed studies of heavy-quark suppression in heavy-ion collisions.
Very good agreement of POWHEG is found with FONLL, in particular for centrally
produced D^0, D^+ and D^*+ mesons and electrons from charm and bottom quark
decays, but also with the generally somewhat higher GM-VFNS predictions within
the theoretical uncertainties. The latter are dominated by scale rather than
quark mass variations. Parton density uncertainties for charm and bottom quark
production are computed here with POWHEG for the first time and shown to be
dominant in the forward regime, e.g. for muons coming from heavy-flavour
decays. The fragmentation into D_s^+ mesons seems to require further tuning
within the NLO Monte Carlo approach.
