"One option is MetaEdit+ (www.metacase.com) as the tool comes with a repository storing not only the metamodel covering abstract syntax (like XMI) but also concrete syntax (diagram, matrix, table) as well as generators. Combination of these is…"
you can use the ATlanMod metamodel zoo available here:
It contains almost 200 metamodels, ranging from UML, BPMN, Java to ACME, BIbTEx or SQL
They are in different formats, like KM3, Ecore, GME, XML, Emfatic.
I think that's the…"