  We present a comprehensive treatment of the spectrum of electric dipole
emission from spinning dust grains, updating the commonly used model of Draine
and Lazarian. Grain angular velocity distributions are computed using the
Fokker-Planck equation; we revisit the drift and diffusion coefficients for the
major torques on the grain, including collisions, grain-plasma interactions,
and infrared emission. We use updated grain optical properties and size
distributions. The theoretical formalism is implemented in the companion code,
SPDUST, which is publicly available. The effect of some environmental and grain
parameters on the emissivity is shown and analysed.
