EOSIO

EOSIO is an open-source blockchain software platform designed for building scalable decentralized applications (dApps). The software provides a permission-based account model, delegated proof-of-stake consensus, and support for high-throughput smart contracts via WebAssembly. Developers write contracts in C++ and deploy them to the EOSIO blockchain.

The protocol uses delegated proof-of-stake with 21 active block producers elected by EOS token holders. Block producers generate blocks and validate transactions; governance is driven by holders voting for block producers. Network resources are allocated through a resource model: RAM must be purchased with EOS, while CPU and bandwidth (NET) are allocated by staking EOS. This design aims to provide predictable performance and low fees by distributing resources rather than charging per transaction.

Smart contracts on EOSIO run as WebAssembly modules, enabling developers to write in C++ and compile to WASM. The platform includes tooling such as the EOSIO Software Development Kit and EOSIO.CDT, and uses multi-index tables for structured data. Accounts include permission controls that allow fine-grained authorization of actions and cross-contract interactions within the same chain.

EOSIO originated with Block.one, which released the software for public use in 2018 after a record-setting initial coin offering that raised substantial funds. The mainnet launched in June 2018. The project emphasizes scalable throughput for dApps and aims to reduce user costs through its resource model. It has faced governance criticisms related to block producer centralization, and Block.one settled with the U.S. Securities and Exchange Commission in 2019 over ICO disclosures.