Diffractive x-ray optics have interesting properties that make them highly attractive for use with x-rays and play a key role in the shaping, direction, and detection for a variety of experiments. In contrast to other kinds of x-ray optics such as mirrors and lenses, diffractive optics allow for precise control of the optical wave front and the realization of complex optical functionalities. The key challenges lie in the fabrication of the diffractive structures by advanced nanolithography techniques, as they need to provide dimensions and placement accuracies down to the nanometer scale. When using diffractive x-ray optics with XFEL radiation, one encounters the additional problem of radiation damage, caused by the extreme radiation levels on the order of terawatts per cm2. In many cases this requires fabricating the diffractive optical elements from diamond, which is the perfect material due to its low x-ray absorption, high melting temperature, and its unsurpassed heat conductivity. I will report on the fabrication and application of diffractive optics for XFEL radiation at a variety of sources and techniques, covering photon energies from the extreme ultra-violet to hard X-rays.