BSD notes

dragonfly bsd has a focus on innovation, and is a recent fork from freebsd.

FreeBSD's focus is on "speed"?

NetBSD's focus is to be ported to everything under the sun.

Dragonfly has a cool rc system it got from netbsd, which allows defining
what rc script depends on what others, and then a program determines
the order to run them in.  FreeBSD appears to share this rc system.

freebsd has an additional sysv-like rc system under /usr/local

dragonfly does not appear to have an mlockall() - even in their web-based
cvs system.  Ok, they had a stub function :) that just returns true.

both dragonfly and freebsd ship with archaic /bin/sh - no shell
functions even.  However, it's relatively easy to build bash on them.
Dragonfly needed to be told it was freebsd to build bash though.

FreeBSD, as rumored, does indeed have background fsck's.

FreeBSD appears to have an affinity for the UFS filesystem still...
I imagine it's one of the few, by now.