I would be really interested to know why people seem to think D-Bus is a "Linuxism". It's a pretty small daemon with an Apache-style license and upstream support for BSD. The only thing I've heard are comments like this where people find that D-Bus is required to run some GTK or Qt application, and those toolkits are viewed as being "Linuxisms", so people put it in that bucket transitively. Is there another reason I missed here?