Actually all languages in Epsilon are independent of the metamodelling
technology (i.e. Ecore) through the use of an intermediate layer we call
EMC (Epsilon Model Connectivity). More information about EMC is provided
in Chapter 2 of the Epsilon book: http://eclipse.org/gmt/epsilon/doc/book/
To support another technology you'll need to implement the IModel
interface and contribute extensions to the extension points specified by
Epsilon. I suspect that the best way to learn more about this is by
looking at existing implementation of IModel. The simplest one is the
one that allows Epsilon to handle plain XML documents: