PSHA, or Probabilistic Seismic Hazard Analysis, can be used to find the probability of different levels of shaking in a region. The results can be used by engineers, planners and insurance companies to design good buildings, create disaster risk reduction strategies and assess the level of economic exposure. This is a great introduction to PSHA.
I use OpenQuake, software produced by GEM (Global Earthquake Model) to perform PSHA. Click to see (and download) my results from Nepal and Bhutan.