The OpenQuake Engine combines the characteristics of various software into one integrated tool. Its unique features are:

free, publicly available and open-source
technical support and documentation available
calculations anywhere in the world
uploading of own hazard, vulnerability and exposure models
combines hazard and risk calculations in a single software, but also supports hazard-only calculations
considers site effects through the usage of Vs30 values
estimates both deterministic and probabilistic seismic hazard and risk
makes use of logic trees to consider the epistemic uncertainty
allows many different types of assets to be modeled (e.g. buildings, population)
incorporates the modeling of spatial correlation of ground motion residuals
allows the consideration of correlation of the uncertainty in the vulnerability
can be used on a single processor laptop as well as on a cloud of computers
produces a full spectrum of products such as stochastic event sets, ground motion fields, uniform hazard spectra, hazard curves and maps, disaggregation plots, loss curves and maps and damage maps.