OT: Is ORBit still faster than DBus?

dbus was designed for the desktop... I think when people try to repurpose it for embedded or other purposes, they have to be prepared to go in and make it actually work in those scenarios. I don't know anything about these use-cases, and they just were never thought about when creating dbus.

minimizing IPC and going peer-to-peer instead of through the bus are both good suggestions.

if you have simple needs just using a raw unix socket instead of a whole IPC "system" might be a good option too. for peer-to-peer the "XMLSocket" protocol that Flash uses is a nice simple one: bidirectional stream of nul-separated strings. Not a lot of code to write for that.

anyway, anyone is welcome to improve libdbus or gdbus or any of the other implementations of dbus, of course! make it do what you need. that's what open source is about.