NetBSD has gone a long way from a rather monolithic userland distributed
in a small number of sets (base, comp, etc, ...) to the idea of "syspkgs",
i.e. modularizing the base operating system into many small packages
in a similar way to what other operating systems do.
The expected benefit of syspkgs is to be able to remove and/or update
single components of the base operating system without rebuilding
everything and it's mother, or be able to replace one component from a
prebuilt binary package, e.g. in the case of security problems run
"env ... pkg_add ... -u ssh.tgz" and be done, where the (sys)packages
would be built by NetBSD's fine
Alan Barrett has done some work on syspkgs recently, and he has posted
his most recent works on this now, see
for more details.
I think there's a bit of way to go to switch to this fully (e.g.
have sysinst integration, ...), but it's a very important step on