The polarization of the Cosmic Microwave Background (CMB) is a powerful probe of the composition and evolution of the Universe.  Recent advances in instrumentation are enabling measurements with unprecedented precision and exquisite control of systematic errors.  In this talk, I will discuss what we can learn about cosmology from CMB polarization in the context of three experiments. SPIDER is a balloon-borne telescope designed to look for a signal from cosmic inflation over the course of two Antarctic flights.  Taurus is a proposed superpressure balloon experiment to study the epoch of reionization on large angular scales.  CMB-S4 is the next generation ground-based experiment, consisting of dedicated telescopes operating from multiple sites to map the microwave sky in many frequency bands.  Together these complementary experiments will allow us to measure the CMB polarization across a wide range of angular scales and probe many outstanding cosmological questions.