Precision Measurements of the Cosmic Microwave Background

We review the current status of measurements of the spectrum, an isotropy and polarization of the CMB, and their impact on cos- mology. We show that there is still a large discovery potential in these measurements, complementing and synergic to other cosmology observations. We also describe a selection of new measurement eff�orts, including high precision measurements of CMB polarization with ground-based, stratospheric balloon and satellite experiments, focusing on the astrophysical and technological limits of these measurements.