RNP is a set of OpenPGP (RFC4880) tools that works on Linux, macOS,
Windows and *BSD built with C++.

rnpkeys allow to generate, import, export, and list keys.

rnp is used to perform encryption, decryption, signing and signature
checks.

librnp is the library used by RNP for all OpenPGP functions, useful
for developers to build against, different from GPGME.