Tether (USDT)

Ethereum is an open-source, public blockchain platform (initially proposed by Vitalik Buterin and developed by the Ethereum Foundation and a global developer community) that executes smart contracts and hosts decentralized applications (dApps) using the native cryptocurrency Ether (ETH). The protocol runs as a permissionless network of node client implementations (e.g., Geth, Erigon, Besu, Nethermind, Lighthouse), provides the Ethereum Virtual Machine (EVM) for contract execution, uses token standards such as ERC-20 and ERC-721, and after The Merge operates under proof-of-stake with ongoing roadmap work — including scalability (rollups/sharding), security, and topics such as quantum-resistance — specified via EIPs and community governance.

Ledger is a hardware cryptocurrency wallet and digital-asset management platform. Its hardware signers are used to manage and authorize transactions for cryptocurrencies including Bitcoin, Ethereum, Solana, XRP, stablecoins and other supported assets, while Ledger Wallet provides functions such as buying, swapping, staking, spending and portfolio tracking. The platform also compares rates from cryptocurrency providers across multiple chains and offers services including Ledger Recover.

Chainlink is a decentralized oracle network developed by Chainlink Labs that provides authenticated off‑chain data and external computation to smart contracts. Its services include Chainlink Price Feeds (decentralized market data), Chainlink VRF (verifiable randomness), Chainlink Functions (secure external API calls), and CCIP (Cross‑Chain Interoperability Protocol); node software and many integrations are published as open source by the project.

Tether is an open-source Linux Wayland desktop bridge for iPhone Continuity features, developed in the zackb/tether repository. It provides Wi-Fi clipboard synchronization and file transfer, while Bluetooth handles SMS/iMessage messaging, notifications, and calls; connections use TLS 1.2 with pinned self-signed certificates. The project includes a Linux daemon, CLI, GTK desktop app, iOS companion app, and browser and mail extensions for OTP handling and autofill. Clipboard sync, file transfer, the iOS app, extensions, and messaging are marked stable, while notification mirroring, phone calls, and AirPods support are experimental. It can be installed through Arch Linux, AppImage, Flatpak, Nix, or from source, and is licensed under the MIT License.