NULS is a blockchain infrastructure that provides customizable services and a global open-source community blockchain project. NULS adopts micro-services to achieve a highly modular underlying architecture, using smart contracts and cross-chain technologies, combined with the ability of ChainBox to quickly build chains, reduce development costs, and accelerate blockchain business application landing. NULS proposes modular thinking and multi-chain parallel microservice architecture and provides a wealth of open-source code modules. Using NULS ChainBox, users can flexibly choose core functional modules such as network module, consensus module, storage module, ledger module, and smart contract to create new blockchains in NULS chain network. They can also define their own business logic through smart contracts with little programming work.