Solmate

OpenZeppelin Contracts

OpenZeppelin/openzeppelin-contracts

Popular

Audited, standard implementations of ERC-20, ERC-721, access control, upgrades and governance.

Solady

Vectorized/solady

Rising

Heavily gas-optimized Solidity snippets and contracts, widely used where every unit of gas counts.

Slither

crytic/slither

Popular

Trail of Bits static analyzer for Solidity and Vyper with 90+ detectors; standard in CI and audits.

Aderyn

Cyfrin/aderyn

Rising

Fast Rust-based Solidity static analyzer from Cyfrin with IDE integration and markdown reports.

Echidna

crytic/echidna

Property-based fuzzer for Ethereum contracts from Trail of Bits, built for invariant testing.

Medusa

crytic/medusa

Rising

Parallel, coverage-guided smart contract fuzzer in Go; Trail of Bits' faster companion to Echidna.

Halmos

a16z/halmos

Rising

Symbolic testing tool from a16z that formally checks Foundry tests over all possible inputs.

Certora Prover

Certora/CertoraProver

Formal verification engine for EVM and Solana contracts using the CVL spec language; open-sourced in 2025.

Mythril

ConsenSysDiligence/mythril

Symbolic-execution security analyzer for EVM bytecode from Consensys; older but still used in audits.