  HEALPix is a Hierarchical, Equal Area, and iso-Latitude Pixelisation of the
sphere designed to support efficiently
  - local operations on the pixel set,
  - a hierarchical tree structure for multi-resolution applications, and
  - the global Fast Spherical Harmonic transform.
  The HEALPix concept and the mathematical software based on it introduced in
this primer meet the challenges which future high resolution and large volume
CMB data sets including the MAP and Planck mission products will present.
