For more than a year now, I've been developing a DSL to write web services
. The DSL has been used in production on major PS3 games and other web applications. To help people getting started with the DSL, I released a 'mini-framework'/example application using the DSL on top of Sinatra, check it out
If you are already familiar with the Grape DSL, it's the same concept but with the following advantages:
contract based design
Note that while this version of the mini-framework uses sinatra as a web engine, the DSL could be used directly on top of Rack, Goliath and potentially Rails 3 (or 4).