[spauldo]

You aren't going to see OpenBSD share a kernel with anyone - it's too different and makes trade-offs the others won't accept. And NetBSD doesn't need the heavyweight kernel FreeBSD uses.

From what I've seen, the BSD community swaps code around on a regular basis. But they pick and choose what code to use based on their own goals. It seems to work pretty well.

[nobodyandproud]

I know nobody will touch this with a ten foot pole, but from a thousand mile view the BSDs seem like a good candidate for a microkernel.