A few points: 1) Spring Roo is not necessarily a more modern approach. It's more similar to Rails. 2) JAX-RS is more like Sinatra than Rails. Generating JSON

A few points: 1) Spring Roo is not necessarily a more modern approach. It's more similar to Rails. 2) JAX-RS is more like Sinatra than Rails. Generating JSON api is already simple in JAX-RS. 3) Not everybody wants ActiveRecord http://www.braintreepayments.com/devblog/untangle-domain-and-persistence-logic-with-curator http://www.braintreepayments.com/devblog/untangle-domain-and... https://github.com/braintree/curator#readme https://github.com/braintree/curator#readme 4) JAX-RS comes with standard Java EE (moot point) 5) You can re-use your Servlet knowledge with JAX-RS to some extend (Filter, setting up web.xml, etc) Not to take anything away from Spring Roo which is a wonderful project.