Based on the various other descriptions of the DBUS features, I kept thinking “this sounds like a message passing model with a bit of CORBA hiding in there”. It’s got a bit of SLP and AMQP/MQTT to it, just on a local machine instead of a distributed network. It’s solving a lot of problems with service discovery, message passing structure, and separating transmission layer details from service API design. Raw sockets/pipes can always be used to pass data (it’s how DBUS does it!), but there’s additional problems of where to send the data and how to ensure data formatting that sockets/pipes do not have the capability of solving by design since they’re simple and foundational to how interprocess communication works in the kernel.