  The initial gluon multiplicity per unit area per unit rapidity, dN/L^2/d\eta,
in high energy nuclear collisions, is equal to f_N (g^2\mu L) (g^2\mu)^2/g^2,
with \mu^2 proportional to the gluon density per unit area of the colliding
nuclei. For an SU(2) gauge theory, we compute f_N (g^2\mu L)=0.14\pm 0.01 for a
wide range in g^2\mu L. Extrapolating to SU(3), we predict dN/L^2/d\eta for
values of g^2\mu L in the range relevant to the Relativistic Heavy Ion Collider
and the Large Hadron Collider. We compute the initial gluon transverse momentum
distribution, dN/L^2/d^2 k_\perp, and show it to be well behaved at low
k_\perp.
