It's a linux library that checks passwords against a database of known words and patterns. You give it a password and it gives you basically one of two answers:

It's a linux library that checks passwords against a database of known words and patterns. You give it a password and it gives you basically one of two answers: "this is based on a known word" or "nope, never seen anything like it before". The database format looks highly obscure and doesn't lend itself to grepping without much effort.