@cindex about
@strong{NNCP} (Node to Node copy) is a collection of utilities
simplifying secure store-and-forward files, mail and command exchanging.

See also this page @ref{Об утилитах, on russian}.

@cindex F2F
@cindex friend-to-friend
@cindex E2E
@cindex end-to-end
@cindex darknet
@cindex DTN
@cindex delay tolerant
@cindex dead drop
@cindex onion encryption
This utilities are intended to help build up small size (dozens of
nodes) ad-hoc @url{https://en.wikipedia.org/wiki/Friend-to-friend,
friend-to-friend} (F2F) statically routed
@url{https://en.wikipedia.org/wiki/Darknet, darknet}
@url{https://en.wikipedia.org/wiki/Delay-tolerant_networking, delay-tolerant}
networks for fire-and-forget secure reliable files, file requests,
Internet mail and commands transmission. All packets are integrity
checked, @url{https://en.wikipedia.org/wiki/End-to-end_encryption,
end-to-end} encrypted, explicitly authenticated by known participants
public keys. @url{https://en.wikipedia.org/wiki/Onion_routing, Onion
encryption} is applied to relayed packets. Each node acts both as a
client and server, can use push and poll behaviour model.
Also there is @ref{Multicast, multicasting} areas support.

Out-of-box offline @url{https://en.wikipedia.org/wiki/Sneakernet,
sneakernet/floppynet}, @url{https://en.wikipedia.org/wiki/Dead_drop,
dead drops}, sequential and append-only
@url{https://en.wikipedia.org/wiki/CD-ROM,
CD-ROM}/@url{https://en.wikipedia.org/wiki/Tape_drive, tape} storages,
@url{https://en.wikipedia.org/wiki/Air_gap_(networking), air-gapped}
computers support. But online TCP daemon with full-duplex resumable data
transmission exists.

Look for possible @ref{Use cases, use cases}!

@cindex GPL
@cindex free software
@cindex licence
NNCP is @url{https://www.gnu.org/philosophy/pragmatic.html, copylefted}
@url{https://www.gnu.org/philosophy/free-sw.html, free software}
licenced under @url{https://www.gnu.org/licenses/gpl-3.0.html, GNU GPLv3}.
It should work on all @url{https://en.wikipedia.org/wiki/POSIX,
POSIX}-compatible systems. Easy @ref{Integration, integration} with existing
@url{https://en.wikipedia.org/wiki/SMTP, SMTP} servers. Single
@url{https://hjson.org/, Hjson} configuration file.

Why create yet another store-and-forward solution when UUCP, FTN and
even SMTP exists? Look in @ref{Comparison, comparison} section!
Simplicity, cryptographic security, sneakernet compatibility and easy
integration with current SMTP servers are the reasons.