Simile allows such models to be specified in terms of stocks and flows, while SBML (generally) encourages models to be expressed in terms of rate equations for biological processes. Both approaches can be thought of as a user-friendly interface for defining differential-equation models. Because they have this in common, it is in principle possible to convert some Simile models into SBML, and some SBML models into Simile. One topic for this group are tools for performing these conversions.
