Pgpgpg takes PGP 2.6 command-line options, translates them and calls GNU Privacy Guard to perform desired actions.
PGP and GNUPG are encryption programs with high-security encryption engines. PGP is available without a fee, but it is not really free software.
GNUPG, on the other hand, is free software, but it has additional features and a different command-line syntax.
The goal of Pgpgpg is to plug in a command-line syntax in front of GNUPG, equal to PGP 2.6.
With Pgpgpg, most scripts and applications written for PGP 2.6 should work normally with GNUPG.
By using Pgpgpg, these applications also benefit from the fact that GNUPG doesn't use the patented, non-free RSA or IDEA algorithm.