Apiary has got Swagger

/author of API Blueprint here/ I would not say this is the case. API Blueprint focuses on different data for various reasons (design-first, documentation-orinented). In order to bring the Swagger support we had to introduce some extension in the format. We are, however, trying to unify the tooling under the hood of the refract project (https://github.com/refractproject/refract-spec/blob/master/n...) through (de)serialization plugins for the Fury.js library (https://github.com/apiaryio/fury.js)

A hosted mock server is part of Apiary suite of tools for the entire API design lifecycle. Others would include interactive documentation, traffic inspector, backend testing and style guide validation. We hope to encourage collaboration and bring the design-first, documentation-oriented approach to the world of API development.