ZeroTier

ZeroTier, Inc. is a software company with a freemium business model based in Irvine, California. ZeroTier provides proprietary software, SDKs and commercial products and services to create and manage virtual software-defined networks. The company's flagship end-user product ZeroTier One is a client application that enables devices such as PCs, phones, servers and embedded devices to securely connect to peer-to-peer virtual networks.

Software tools
ZeroTier markets proprietary tools, which are licensed under a Business Source License 1.1, intended to support the development and deployment of virtual data centers:

In 2021, the product line consists of the following tools:
 * ZeroTier One, first released in 2014, is a portable client application that provides connectivity to public or private virtual networks.
 * Central, a web-based UI portal for managing virtual networks.
 * libzt (SDK), a linkable library that provides the functionality of ZeroTier One but that can be embedded in applications or services.
 * LF (pronounced "aleph"), a fully decentralized fully replicated key/value store.

Client
The ZeroTier client is used to connect to virtual networks previously created in the ZeroTier Central web-based UI. Endpoint connections are peer-to-peer and end-to-end encrypted. STUN and hole punching are used to establish direct connections between peers behind NAT. Direct connection route discovery is made with the help of a global network of root servers via a mechanism similar to ICE in WebRTC.

Controller
Virtual networks are created and managed using a ZeroTier controller. Management is done using an API, proprietary web-based UI (ZeroTier Central), open-source web-based. Using root servers other than those hosted by ZeroTier Inc. is impeded by the software's license.

Packages
ZeroTier One is available on multiple platforms and in multiple forms:
 * Microsoft Windows installer (.msi)
 * Apple Macintosh (.pkg)
 * iOS for iPhone/iPad/iPod
 * Docker
 * IoT Stack
 * Source code on GitHub
 * Linux binaries (DEB & RPM)
 * Linux snap package (works across distributions)
 * Linux library
 * Arch Linux Community package
 * Android App on Google Play
 * Qnap (.qpkg)
 * Synology packages (.spk)
 * Western Digital MyCloud NAS EX2, EX4, EX2 Ultra (.bin)
 * FreeBSD has a port and a package
 * OpenWRT has a community-maintained port on GitHub
 * MikroTik's RouterOS
 * Teltonika Network's RutOS
 * DynFi, a Dynamic Firewalls solution