QNX and L4 has had competitive performance since forever. And they have been heavily used in embedded systems, especially QNX. Basically, in my mind the only th

QNX and L4 has had competitive performance since forever. And they have been heavily used in embedded systems, especially QNX. Basically, in my mind the only thing that stood between QNX and total world domination was that it wasn't open source. Many flavors of L4 are open source, but they're just a piece of what you need for a complete OS.