How does D-Bus differ from XML-RPC and SOAP?
Start by reading Q:9. In SOAP and XML-RPC, RPC calls are transformed into an XML-based format, then sent over the wire (typically using the HTTP protocol), where they are processed and returned. XML-RPC is the simple protocol (its spec is only a page or two), and SOAP is the full-featured protocol. XML-RPC and SOAP impose XML parsing overhead that is normally irrelevant in the context of the Internet, but significant for constant fine-grained IPC among applications in a desktop session. D-Bus offers persistent connections and with the bus daemon supports lifecycle tracking of other applications connected to the bus. With XML-RPC and SOAP, typically each method call exists in isolation and has its own HTTP connection.
