CFML is a tool that can be used to verify Caml programs using the Coq proof assistant. It is based on Characteristic Formulae, which have been developed in Charguéraud's thesis.

CFML consists of two parts: a generator that parses Caml code and produces characteristic formulae expressed as Coq axioms (the generator itself is implemented in Caml), and a Coq library that provides tactics for manipulating characteristic formulae interactively.

A collection of algorithms and data structures, some purely functional and other using imperative code, have been verified using CFML.