Coq is a formal proof management system: a proof done with Coq is mechanically checked by the machine. In particular, Coq allows:

License: GNU LGPL.
Tags: logic, automated theorem proving.
Interfaces: command line, X.
Source language: OCaml.
Maintainer: Benjamin Monate.
Developer: Benjamin Monate.
Contributors: Jean-Cristophe Filliâtre, Pierre Letouzey, Claude Marché.
Homepage: http://coq.inria.fr/.
Documentation: http://coq.inria.fr/doc-eng.html.
Source repository: http://coq.inria.fr/distrib-eng.html.
Bug database: http://logical.futurs.inria.fr/cgi-bin/bugzilla/index.cgi.
Support: coq-club@pauillac.inria.fr.