rippled

rippled is the reference server implementation for the XRP Ledger, a distributed, open-source payment ledger designed for fast, low-cost cross-border transactions. It is developed and maintained by Ripple and a community of contributors. Written in C++, rippled is released under the Apache License 2.0 and runs on Linux, Windows, and macOS.

Function and design: As a node in the XRP Ledger network, rippled validates, relays, and records transactions, and participates in the ledger consensus process that forms the core of the network. The XRP Ledger uses the Ripple Protocol Consensus Algorithm (RPCA), a non–proof-of-work consensus mechanism where validators exchange proposals and reach agreement on the next ledger. Each node uses a Unique Node List (UNL) to determine which validators it trusts; consensus requires a supermajority of the UNL. When consensus is achieved, the proposed ledger version is closed and becomes the new validated ledger.

Interfaces and operation: rippled exposes client APIs, including JSON-RPC and WebSocket endpoints, for submitting payments, querying balances, and reading ledger data. It can run in validator mode, contributing to network consensus, or in non-validating modes as a standard peer. The software is configurable, with options for the UNL, validator identities, fee settings, and other operational parameters.

Impact and status: Since its early releases, rippled has been the primary reference implementation for the XRP Ledger and is widely used by validators, exchanges, and gateways. It is continuously updated by Ripple and the community to improve performance, security, and compatibility with the XRP Ledger protocol.