Published in "Beyond the Desert", ed. H.V. Klapdor-Kleingrothaus, 1999

Abstract. I review the present status of the Cosmic Microwave Background, with some emphasis on the current and future implications for particle physics.

Keywords: CMB - phenomenology - speculation

Table of Contents

BACKGROUND

WHAT DO WE KNOW?

Astrophysics

Cosmology

Particle Physics

Inflation

Defects

Other Paradigms?

FUTURE EXPERIMENTS

MAP and Planck

CONCLUSIONS

REFERENCES