the chance not needing to start up many services to have a modern *Nix*Free*Li*net* OS
that is running like a quick, responsive machine, three generations older than the one needed for CentOS.
The "Free" in FreeBSD - is for Freedom: we choose what services our machines run, no fucking installer.
The "Free" in FreeBSD - is for OptIn not to be Opted in by default.
And the BSD in FreeBSD - stands for structure, clean, deterministic behaviour, not that clutter a Linux Distribution is built uppon
(have a look at linuxfromscratch)
Just download the FreeBSD source tree kernel and userland, you will recognize every source for each non-builtin-command is placed in a directory with a make file.
If you want to alter something just edit the source "make" it, and install it in your system.