# Using an EMF package as a model with Epsilon programs

Epsilon can be used with a range of modelling technologies, including EMF, MDR and plain XML. Before launching an Epsilon program, the models to be consumed or produced by the program must be specified. This article describes the way in which Epsilon programs can be configured to access an EMF package (i.e. an EMF metamodel), treating it as a model.

When launching an Epsilon program, the launch configuration dialog includes a "models" tab. To configure an Epsilon program to use an EMF package as a model, click the "models" tab, click "Add", and select "Registered EMF EPackage."

The resulting dialog box contains several options that are used to specify how Epsilon will access the model at run-time:

Name
  The identifier used to access this model from the Epsilon program.
Aliases
  Additional identifiers for accessing this model.
File
  The location of the XML document in this workspace.
Meta-model URI
  The EMF namespace URI of the EMF EPackage (metamodel).