All materials alter their internal structure in response to externally imposed loads. The simplest example is elastic deformation, in which the structural change (for metals and ceramics, anyhow) is simply streching or compression of the atomic bonds. Higher loads can cause more dramatic structural changes. Because some of these changes are partially or completely reversed when the load is removed, it is often useful to study them in situ (literallly, "in place") while the load is still applied. To do this, we make use of high energy, high intensity x-rays available from synchrotron sources (such as the Advanced Photon Source, or APS). With these x-rays, we can measured changes in the strain (and therefore stress) in the material as well as track the evolution of structural defects such as dislocations. These studies have the potential to lead to a better understanding of deformation and fracture mechanisms in metallic glasses as well as the development of new metallic-glass-matrix composite materials.