This book positions itself to be the basic reference for developers who are designing distributed computing systems that use the dominant pattern of REST (Representational State Transfer). The authors describe how most API standardization still centers around human readable documentation of fiat standards instead of machine readable formats which have been around for some time now, and the benefits of moving to a more machine-centered approach. The problem of upgrading an API can be solved at the design stage by the right choice of hypermedia and the use of existing standards when possible. They take the approach of devoting the first half to elementary examples of resource representations, in html, json, xml, or forms derived from these standards, without listing specific examples of code to generate or consume those representations. The latter half describes some standards which did not exist or were not widespread at the time of the previous version of the book, and while it does not try to be an encyclopedic list of APIs, it does point to online repositories where new standards will be published.
It was a good reference book for someone who isn’t currently an expert in the area covered, with down to earth (if not to say simplistic) examples to illustrate the best practices they discuss.