  We report the results of an extensive set of direct numerical simulations of
forced, incompressible, magnetohydrodynamic turbulence with a strong guide
field. The aim is to resolve the controversy regarding the power law exponent
(\alpha, say) of the field perpendicular energy spectrum E(k_\perp) \propto
k_\perp ^ {\alpha}. The two main theoretical predictions, \alpha=-3/2 and
\alpha=-5/3, have both received some support from numerical simulations carried
out by different groups. Our simulations have a resolution of 512^3 mesh
points, a strong guide field, an anisotropic simulation domain, and implement a
broad range of large-scale forcing routines, including those previously
reported in the literature. Our findings indicate that the spectrum of well
developed, strong incompressible MHD turbulence with a strong guide field is
E(k_{\perp})\propto k_{\perp}^{-3/2}.
