Solidity

Solidity is a statically typed, curly-brace programming language built specifically for writing programs that execute on the Ethereum blockchain and other EVM-compatible networks. First proposed in 2014 by Gavin Wood, one of Ethereum's original core developers, its syntax borrows from JavaScript, C++, and Python, so it feels familiar to mainstream developers while adding constructs unique to blockchain programming, such as contract inheritance, function modifiers, and native handling of addresses and cryptocurrency values.

Developers write Solidity source code and compile it into bytecode that runs on the Ethereum Virtual Machine (EVM), the execution engine built into Ethereum and dozens of compatible chains. Once deployed, that bytecode is public and, in most cases, permanent: anyone can inspect it, but changing it usually means deploying an entirely new contract. This is why Solidity is the language behind most smart contracts in production today, including ERC-20 tokens, NFT collections, decentralized exchanges, lending protocols, and DAOs.

Because the EVM bytecode format has become a de facto standard, many other chains, including BNB Smart Chain, Polygon, Avalanche, Arbitrum, and Base, support Solidity directly, letting developers deploy the same contract code across multiple networks with little or no change. Writing, testing, and deploying contracts typically involves frameworks such as Hardhat or Foundry, along with browser-based tools like Remix.

Because deployed contracts often hold real funds and cannot easily be patched, coding mistakes in Solidity can be extremely costly: reentrancy bugs, integer overflow, and flawed access controls have caused some of the largest exploits in crypto history. Serious projects therefore have their code professionally audited, rely on well-tested libraries such as OpenZeppelin, and often design contracts to be upgradeable. Despite more than a decade of development, Solidity is still versioned below 1.0, reflecting its continuous evolution alongside Ethereum itself.