Jet physics is again flourishing as a result of Chandras ability to resolve high-energy emission from the radio-emitting structures of active galaxies and separate it from the X-ray-emitting thermal environments of the jets. These enhanced capabiliti
es have coincided with an increasing interest in the link between the growth of super-massive black holes and galaxies, and an appreciation of the likely importance of jets in feedback processes. I review the progress that has been made using Chandra and XMM-Newton observations of jets and the medium in which they propagate, addressing several important questions, including: Are the radio structures in a state of minimum energy? Do powerful large-scale jets have fast spinal speeds? What keeps jets collimated? Where and how does particle acceleration occur? What is jet plasma made of? What does X-ray emission tell us about the dynamics and energetics of radio plasma/gas interactions? Is a jets fate determined by the central engine?
