For 50 years, the only astronomical source with measured soft X-ray polarization was the Crab nebula, initially detected with sounding rockets. Now we finally have the Imaging X-ray Polarimetry Explorer mission on orbit, which  has already measured complex X-ray polarization signals from dozens of neutron  star and black hole sources, with over 100x the sensitivity of the initial experiments. I summarize the motivation for such polarization studies, the technology advances that made IXPE possible, and some exciting results from our first year's program. As the wider community gets involved, additional novel probes of high energy astrophysical sources are expected soon.