Gnu Privacy Guard

The GNU Privacy Guard (GnuPG) is the OpenPGP implementation of the GNU project. GnuPG is fully OpenPGP compliant, supports most of the optional features and provides some extra features. GnuPG is used as the standard encryption and signing tool of all GNU/Linux distributions.

GnuPG is freely available for GNU/Linux, nearly all other Unix systems, Microsoft Windows systems and a few other operating systems. As a GNU program it can be used commercially or non-commercially without any costs.

Commercial grade support, consulting and custom development related to GnuPG is available through g10 Code GmbH, founded by the principal author of the software.