Overview of Current and Planned CMB Ballooning Efforts

Balloon-borne experiments have a unique role in probing the polarization of the CMB. They enable access to frequencies that can not be probed by ground-based instruments, they can straight-forwardly measure signals on large angular scales, and they serve as test-beds for technologies that are ultimately used on space missions. With these roles in mind, I will discuss the status of the three NASA-funded experiments EBEX, SPIDER and PIPER, and their complementarity with ground-based efforts. I will also discuss plans for next generation instruments, with which the detector count is expected to increase by another factor of 10 to about 10,000.