NNCP (Node to Node copy) is a collection of utilities simplifying secure store-and-forward files, mail and command exchanging. This utilities are intended to help build up small size (dozens of nodes) ad-hoc friend-to-friend (F2F) statically routed darknet delay-tolerant networks for fire-and-forget secure reliable files, file requests, Internet mail and commands transmission. All packets are integrity checked, end-to-end encrypted, explicitly authenticated by known participants public keys. Onion encryption is applied to relayed packets. Each node acts both as a client and server, can use push and poll behaviour model.

Out-of-box offline sneakernet/floppynet, dead drops, sequential and append-only CD-ROM/tape storages, air-gapped computers support. But online TCP daemon with full-duplex resumable data transmission exists.

F/OSS software that implements invitation-only discussion groups for journalists and activists to communicate. Interestingly, it is designed to make use of whatever networking methods are available to it. It's possible to export messages to bundles transported on removable media (ala QWK Mail) to synch Briar instances (albeit with considerable latency).