Seventeen years after its initial publication at ICSE 2000, the Representational State Transfer (REST) architectural style continues to hold significance as both a guide for understanding how the World Wide Web is designed to work and an example of how principled design, through the application of architectural styles, can impact the development and understanding of large-scale software architecture. However, REST has also become an industry buzzword: frequently abused to suit a particular argument, confused with the general notion of using HTTP, and denigrated for not being more like a programming methodology or implementation framework.

REpresentational State Transfer (REST) guided the creation and expansion of the modern web. What began as an internet-scale distributed hypermedia system is now a vast sea of shared and interdependent services. However, despite the expressive power of REST, not all of its benefits are consistently realized by working systems. To resolve the dissonance between the promise of REST and the reality of fielded systems, we critically examine numerous web architectures. Our investigation yields a set of extensions to REST, an architectural style called Computational REST (CREST), that not only offers additional design guidance, but pinpoints, in many cases, the root cause of the apparent dissonance between style and implementation. Furthermore, CREST explains emerging web architectures (such as mashups) and points to novel computational structures.