Configuration Management - e.g. Puppet, Saltstack, Ansible, Chef; or if you're old school cfengine. They are good at bringing systems to a known state; but not

Configuration Management - e.g. Puppet, Saltstack, Ansible, Chef; or if you're old school cfengine. They are good at bringing systems to a known state; but not as good for cleaning systems up. If not watched carefully, all of the cruft in your /etc directory will be ported to your CM because someone needs it.