The GMPE compendium is maintained by John Douglas, a Chancellor's Fellow (Lecturer) at the University of Strathclyde, Glasgow, UK. From the website:
Ground motion prediction equations (GMPEs) are mathematical expressions to estimate the earthquake shaking that would be felt at a site given the occurrence of an earthquake of a certain size at a nearby location. GMPEs play a key role in engineering seismology and earthquake engineering as they are used to provide estimates of the forces that a structure may undergo during an earthquake. GMPEs generally provide a prediction in terms of an scalar intensity measure (IM) of the earthquake shaking. The compendium provided by this website provides details of published models for the commonly-used IMs.