The AMALTHEA model is specified with the Eclipse Modeling Framework (EMF). Eclipse/Java developers can use the AMALTHEA Platform where the generated Java classes of the model are included. The underlying Xcore definition of the model is part of the model plugin.
Both definitions (the original Xcore file and the derived Ecore files) can be found here.
For developers that are not using Java or Eclipse, the specification is also provided in the XML and XSD format. The XML related files can be found here.
The AMALTHEA model refers to the Ecore model definition (http://www.eclipse.org/emf/2002/Ecore).
This definition (generated automatically during conversion) is also stored in the archive.