Yes, it's useful both in theory and practice. Mind you, I would say that: full disclosure: I'm a committer on the Apache Isis framework. But over the last 5 y

Yes, it's useful both in theory and practice. Mind you, I would say that: full disclosure: I'm a committer on the Apache Isis framework. But over the last 5 years the framework has been developed based on the needs of real-world apps that I'm fully involved in building; we then factor out stuff as need be to develop the framework. I'm always amazed at the abstraction level pretty much all the other frameworks out there... just so much hacking around with technical stuff rather than focusing on the domain. The Apache Isis framework pretty much forces the dev to work only in terms of the domain. But judge for yourself: Estatio (http://github.com/estatio/estatio http://github.com/estatio/estatio) is the real-world app (for invoicing) that we work on; there are also technical addons (http://isisaddons.org http://isisaddons.org) and generic subdomain modules (http://catalog.incode.org http://catalog.incode.org) which we've also factored out.