Node Configuration Manager (NCM) components are Perl modules that run on each managed Linux node to ensure the configuration matches what is requested in the profile. Components are not executed standalone but instead launched by ncm-ncd.
They are part of Quattor.
You can find the latest user documentation at: https://quattor-documentation.readthedocs.io/en/latest/.
There is also a developer guide.