A Web application's architecture is heavily influenced by the design decisions, both implicit and explicit, that have been made by framework developers. Sometimes these decisions are consciously accepted as being in line with the intended overall system architecture. More often, though, they are accepted simply because developers assume they embody the state of the art of development practices.
ROCA is an attempt to define a set of recommendations — independent of any particular framework, programming language, or tooling — that embodies the principles of what we consider to be good web application architecture. Its purpose is to serve as a reference, one that can be implemented as-is or be compared to other approaches to highlight diverging design decisions.