Projects sharing features with Bitcoinj

This project is a multi-chain cryptocurrency wallet and self-custodial asset manager. It allows users to store, manage, and transfer digital assets across multiple blockchain networks while maintaining exclusive local control over private keys. The application implements multisignature security, requiring a quorum of digital signatures from multiple participants to authorize transactions for shared funds. It also provides tools for self-custodial management, including hierarchical deterministic key derivation and local private key storage. The platform covers a range of financial operations,

This project is a blockchain node software implementation that maintains a decentralized ledger using the Ouroboros proof-of-stake consensus protocol. It provides a complete environment for operating a distributed record, including a cryptocurrency wallet backend and a peer-to-peer network layer. The system is distinguished by its use of a UTXO-based ledger model and a diffusion-based state synchronization layer for node communication. It integrates a Public Key Infrastructure with TLS-authenticated communication to secure inter-node traffic and employs hierarchical deterministic key derivati

Grin is a protocol implementation and blockchain node that provides a confidential transaction system. It uses Pedersen Commitments and homomorphic encryption to verify value integrity and ensure a consistent money supply without revealing specific transaction amounts or participant identities. The project distinguishes itself through an interactive transaction exchange model, where wallets coordinate multi-round data exchanges to build signed transactions. To maintain anonymity, the system supports onion-routed transaction delivery and masks originating IP addresses through specialized relay

Lux is a blockchain infrastructure project providing a distributed ledger and a smart contract platform. It utilizes a hybrid proof-of-work and proof-of-stake consensus mechanism to secure decentralized transactions and maintain network stability. The project features a peer-to-peer ecosystem that includes a decentralized file storage system for immutable data, a masternode network for governance, and a cross-chain asset bridge. It distinguishes itself with an ASIC-resistant hashing algorithm optimized for general-purpose CPUs and a decentralized order book for matching trades without a centr

rippled is a peer-to-peer node implementation for the XRP Ledger. It serves as a distributed ledger consensus engine and a blockchain API gateway, allowing servers to validate transactions and maintain a shared, immutable sequence of ledger state. The project features a built-in decentralized exchange engine capable of executing atomic cross-currency payments and managing order books. It includes an on-chain asset management system for issuing and controlling fungible tokens and NFTs, as well as a Byzantine Fault Tolerant system for coordinating validators. The platform provides comprehensiv

Monero is a privacy-focused cryptocurrency and proof-of-work blockchain designed for private digital payments. It utilizes a peer-to-peer network and a distributed ledger to allow users to send and receive currency while hiding transaction senders, receivers, and amounts. The system achieves financial confidentiality through the use of ring signatures for sender obfuscation and RingCT with Bulletproofs to hide transaction values. To ensure network security and decentralization, it employs a memory-hard proof-of-work algorithm optimized for general-purpose CPUs. The project provides a full no

BTCPay Server is a non-custodial payment gateway and invoice manager designed for accepting Bitcoin and other cryptocurrencies directly into a private wallet. It serves as a self-hosted payment infrastructure that allows merchants to manage digital invoicing and storefronts without relying on third-party intermediaries. The system distinguishes itself through a non-custodial wallet architecture that ensures private keys remain on the user's own hardware or server. It integrates the Lightning Network for instant, low-cost transactions and provides a hardware-wallet signing bridge to secure tra

BlueWallet is a Bitcoin wallet application that provides a mobile interface for managing Bitcoin assets, including standard wallets and specialized tools for Lightning Network payments. It serves as a coordinator for various wallet types, including multisig vaults and watch-only interfaces. The project distinguishes itself through advanced security and privacy features, such as decoy storage architecture to hide assets during forced disclosure and custom entropy generation using physical dice or coins. It supports air-gapped transaction management via QR codes and PSBT integration for hardwar

Signal-Android is an end-to-end encrypted messaging platform designed to ensure that only the sender and recipient can access communication content. The project provides a comprehensive framework for secure, asynchronous message initiation and key agreement, allowing users to establish private channels without requiring simultaneous online presence. It relies on a state machine architecture to manage communication epochs and authentication, ensuring consistent security transitions throughout the messaging lifecycle. The platform distinguishes itself through a hybrid cryptographic approach tha

Solana Web3.js is a TypeScript and JavaScript client library for interacting with the Solana blockchain. It functions as a web3 client that provides an RPC wrapper for managing network requests and a toolkit for querying account state and executing on-chain program instructions. The library includes a specialized cryptography interface for generating key pairs and performing asynchronous signing and verification using web cryptography standards. It also provides a serialization tool for encoding and decoding data between JavaScript objects and byte buffers to match on-chain program state. Th

This library provides a collection of low-level mathematical primitives for Curve25519 and Ristretto group operations. It serves as a foundation for building secure cryptographic protocols, offering tools for elliptic curve arithmetic, key exchange, and digital signature generation. The implementation prioritizes side-channel resistance by utilizing constant-time arithmetic logic across all operations, ensuring that secret-dependent timing variations are prevented. It leverages the Rust type system to enforce state validity, making illegal group elements unrepresentable at compile time. To ma

JRuby is a Ruby language implementation that runs on the Java Virtual Machine. It serves as a cross-language runtime and execution environment, allowing Ruby code to run on the JVM and share memory with Java applications. The project functions as a bridge between Ruby and Java, enabling Ruby scripts to call Java classes and libraries directly. It also provides a mechanism to embed a Ruby interpreter into Java applications to allow for dynamic scripting. The runtime leverages the JVM for system scalability and ensures a consistent execution environment across different operating systems.

This project is a Rust SDK and client library for the Fuel blockchain. It serves as a smart contract development kit used to compile, deploy, and test blockchain contracts in both local and remote environments. The library includes a binding generator that creates type-safe Rust code from contract methods, ensuring compile-time safety for blockchain function calls. It also provides a local sandbox runtime to launch network nodes and simulate wallet activity for decentralized application testing. The toolset covers blockchain wallet management, transaction signing, and state querying through

Frege is a purely functional programming language that compiles to JVM bytecode, providing Haskell-like semantics for the Java platform. It is built around a Haskell-inspired compiler that implements non-strict evaluation and a static type inference system to ensure data immutability and prevent side effects. The project distinguishes itself through a sophisticated type system featuring rank polymorphism, type-class based dispatch, and static purity enforcement. It includes a JVM language bridge and a foreign function interface that map Java classes and interfaces into functional types, allow

This project provides a collection of infrastructure components for multichain wallet integration, including a cryptographic library for cross-chain transaction signing and a curated repository for cryptocurrency asset metadata. It serves as a central hub for managing token logos, contract addresses, and technical specifications for digital assets across multiple blockchains. The system includes a Model Context Protocol server that exposes real-time blockchain data and technical documentation to large language models. It further extends this AI integration by providing a standardized tool-cal

Chia is a decentralized blockchain platform that uses a proof-of-space-and-time consensus mechanism, enabling energy-efficient farming on commodity hardware. It implements a full blockchain node, farmer, harvester, timelord, and wallet in Python, prioritizing readability and cross-platform compatibility. The platform manages transactions through a simplified UTXO model that minimizes on-chain state and supports fast validation. The project introduces Chialisp, a Turing-complete functional smart contract language designed for secure and auditable financial transactions. It features a pooling p

This project is a protocol tool, server, and indexer for managing digital artifacts and commodities on the Bitcoin blockchain. It provides the core infrastructure for inscribing arbitrary data onto individual satoshis to create permanent, immutable assets and collectibles. The system implements the Runes protocol for creating, minting, and transferring native digital commodities. It distinguishes itself by tracking satoshi rarity based on mining order and establishing parent-child provenance mapping to verify the lineage and authenticity of on-chain inscriptions. The project covers a broad s

ethers.js is an Ethereum JavaScript library used to interact with the Ethereum blockchain by querying state and sending transactions via JSON-RPC providers. It functions as a smart contract wrapper, a Web3 provider interface, and a system for managing wallets and cryptographic signatures. The project provides a dedicated Ethereum Name Service resolver for translating human-readable names into blockchain addresses through forward and reverse lookup operations. It also includes an implementation for managing private keys and mnemonic phrases to sign digital data and authorize on-chain transacti

bitcoinjs-lib is a JavaScript library for building Bitcoin transactions, generating addresses, and managing keys in both Node.js and browser environments. It provides a complete Bitcoin development toolkit covering address generation across standard, SegWit, P2SH, and multisig formats for mainnet and testnet networks, along with hierarchical deterministic key derivation following BIP32, BIP39, BIP44, and BIP49 standards. The library offers a comprehensive transaction engine that handles ECDSA and Schnorr signatures on the secp256k1 curve, supports Partially Signed Bitcoin Transaction (PSBT) f

Lnd is a full implementation of the Lightning Network protocol, functioning as a Bitcoin Layer 2 daemon that manages payment channels and settles transactions on the Bitcoin blockchain. It serves as an off-chain payment processor and a cryptographic wallet manager, enabling the execution of instant, scalable transactions through a network node. The project distinguishes itself through a focus on secure node networking and programmatic control. It provides gRPC and REST API servers for automating payment workflows and utilizes macaroon-based authorization to delegate granular permissions via c

web3.js is a TypeScript development framework and library for integrating applications with the Ethereum blockchain. It serves as an Ethereum JSON RPC library for querying data and sending transactions, a smart contract interface for interacting with on-chain logic, and a wallet integration toolkit for managing private keys. The project provides specialized capabilities for blockchain node communication, enabling the execution of smart contract functions and the management of Ethereum accounts. It includes tools for web3 address resolution to translate human-readable names into machine-readab

fuels-ts is a TypeScript SDK and development toolkit for the Fuel blockchain. It provides a library for executing transactions and querying blockchain state, alongside a set of utilities for smart contract development and deployment. The toolkit includes a local blockchain node runner that supports hot-reloading to enable rapid testing and iteration. It further distinguishes itself by generating type-safe TypeScript definitions from smart contract specifications to ensure compile-time validation of function calls. The project covers a broad range of capabilities including wallet derivation u

Optimism is an Ethereum optimistic rollup stack designed to increase transaction throughput by processing transactions on a secondary layer and settling the state on the Ethereum mainnet. It functions as a scaling framework that utilizes a rollup sequencer to order transactions, produce blocks, and submit batched data to the primary blockchain. The system features a fraud proof system that uses on-chain instruction emulation to resolve disputes and verify the correctness of state transitions. It includes a dedicated toolset for deploying and upgrading the smart contracts required to bootstrap

Parity Ethereum is a software implementation of an Ethereum client node that maintains a local copy of the ledger and validates network transactions. It functions as a blockchain network peer and an Ethereum Virtual Machine runtime, providing the environment necessary to process smart contract bytecode and update network state. The project includes systems for cryptographic key management to generate and store the private keys used to sign secure transactions. It enables the operation of a blockchain node and provides mechanisms for Ethereum network synchronization to match the current state

This project is a comprehensive educational guide and technical manual for the Ethereum blockchain. It provides structured instruction on blockchain fundamentals, smart contract development, and the architectural principles of decentralized applications. The resource covers technical domains including smart contract security auditing, network administration, and web3 programming. It details the implementation of token standards, the use of mnemonic seeds for wallet integration, and the creation of censorship-resistant application architectures. The documentation extends to system-level opera

Buck is a multi-language build system and modular build orchestrator designed to compile and package software modules across different programming languages and hardware platforms. It functions as a hermetic build tool, isolating the build process from the host system to ensure consistent and reproducible outputs. The system manages polyglot software builds by organizing code into small, independent units to facilitate faster compilation. It operates as a cross-platform package manager that creates and distributes software components across various operating systems and language ecosystems.

Earthly is a containerized build system and Docker build framework designed for creating reproducible build pipelines. It ensures environment consistency by executing every build step inside an isolated container, combining the isolation of container images with dependency tracking and parallel execution. The system differentiates itself through a focus on hermeticity and multiplatform support, allowing for the generation of container images targeting multiple CPU architectures within a single execution flow. It maintains a hermetic build environment by isolating network access and utilizing