A RESTful web service, is a Web Service that conforms to Representational State Transfer (REST) practices.
With regard to the Future of the Federation we want to see a full and robustly supported Rest API supported across a number of Fedwiki Server implementations.
Representational State Transfer (REST) is a software architecture style consisting of guidelines and best practices for creating scalable web services - wikipedia 
A REST API is an API that provides it's interface through REST. Here we list a number of services and projects that help you develop and maintain a robust REST API.
⇒ REST API ⇒ Speech Acts ⇒ The RESTfulness of Speech Acts. wayback