The Center for X-ray Optics offers a concise discussion and many graphs illustrating the primary interactions of low-energy X-rays within matter. Users can find a database of atomic scattering factors which are used to characterize the interactions between X-rays and matter. The website provides the electron level widths, electron binding energies, atomic properties, and material properties for the elements. Visitors can generate plots of refraction indices, attenuation length of a solid, X-ray transmissions for solids and gases, X-ray reflectivity, bend magnet spectrum, and transmission grating efficiency. This website offers an effective means for visualizing X-ray data.