Facter is Puppet’s cross-platform system profiling library. It discovers and reports per-node facts, which are available in your Puppet manifests as variables.

• The list of core facts lists and describes every built-in fact that ships with Facter.
• The custom fact reference serves as an example-driven primer and quick reference for fact authors.
• The custom facts walkthrough explains in detail how to write and distribute your own custom or external facts.
• The Facter release notes document Facter’s history.