[dale_glass]

What kind of GUI app has a performance problem with the message bus?

We're in the age of 4K, 60 FPS rendering. If any GUI application has a message bus that's strained enough to impact performance, then either the application isn't made for humans (because if all that stuff is doing anything it'd result in a screen updating far faster than it could be read), or there's some horrible bug somewhere that produces a flood.

[rwmj]

In reality none, but developers often think it's not a "real" message bus unless you have to install it on a separate cluster of machines (like AMQP), or it breaks your desktop randomly (dbus). The idea that a message bus could be part of the application and very lightweight is unexpected.