Abstract: Xenon two-phase technology, employing liquid xenon for detector mass and gaseous xenon for charge signal amplification, has found its killer application in direct detection of dark matter interactions. As a result, two-phase xenon detector technology has made great strides in the past decade, with key developments in xenon purification, light collection, application of high electric fields, and calibration techniques. These developments will be described, along with our latest understanding of liquid xenon charge and light production by ionizing radiation.