Unlike XML-RPC , which only models these static interfaces in XML, Coins adds considerable robustness. Any implementation of Coins requires an arms-length relationship between XML documents and Java objects. One consequence of this is a lifting of dependencies between the programs which are interchanging information. Data elements can be added by an updated program without having to syncronize updates to the other programs. XML has always held the promise of facilitating the transfer of data between programs.
Coins is a programming paradigm that can fulfill that promise.
When passing documents, the outer elements are typically well-known, but often the inner elements need to be treated simply as data. It seems excessive to require a schema to fully specify all elements. Quick fully supports the concept of opaque data, where some of the elements in a document are the content which is being routed to another process, or perhaps written to a log file.