Cryptozombies - free interactive tutorial to learn Solidity by making your own zombie crypto-collectibles game
Vyper.fun - free interactive tutorial to learn Vyper by building a Pokémon Game
Solidity by Example - introduction to Solidity concepts with simple examples. Pairs well with the Solidity Docs and this Solidity 101 overview
Vyper by Example - introduction to Vyper concepts with simple examples, mirroring the format of Solidity by Example. Pairs well with the Vyper Docs
lil-web3 - simple, intentionally-limited versions of web3 protocols & apps to better understand how they work, by Miguel Piedrafita
DeveloperDAO Knowledge Base - repository with web3 development resources by Developer DAO
DeFi Developer Roadmap by Officer CIA - curated DeFi development & general blockchain research and tools
Smart Contract Programmer's Youtube Channel - step-by-step Solidity coding and test demonstrations of common smart contract patterns, features, functions, etc.
eth.build - web3 educational sandbox with drag-and-drop and visual educational building blocks
scaffold.eth - top to bottom resources for building dApps on Ethereum, by Austin Griffith. Also check out additional links in his Ethereum Dev Speed Run.
jenny.lol Solidity Links - collection of intermediate to advanced solidity concepts, repos, gas optimizations, and tweet threads
solidity-mentorship - use case by use case program to learn solidity by Alberto Cuesta Cañada
SolidityQuiz.com - Solidity quiz questions with dropdown options and free response, varying in difficulty from intermediate to expert
smartcontract.engineer - individual simple challenges increasing in complexity, with tests and solutions, in Solidity and Vyper
Learning Solidity Video Tutorials - list of Solidity Tutorial YouTube videos by Will it Scale
Ethernaut - a Web3/Solidity based war game, played in the Ethereum Virtual Machine, where each level is a smart contract that needs to be 'hacked'
OpenZeppelin Learn - comprehensive guides for each step of development on Ethereum
The EVM Handbook - curated list of EVM resources
Complete Guide to Full Stack Ethereum Development - building full stack dApps with React, Ethers.js, Solidity, and Hardhat by Nader Dabit
How to Become an Ethereum Developer Guide - step by step to become an Ethereum dev by @cupOJoseph
KnowEthereum - curated resources for the Ethereum ecosystem
How to Learn Solidity - a step by step tutorial on a demo Solidity dApp by Ryan Molecke
Solidity Trivia - advanced demos and explanations for Solidity trivia shared on twitter via the profile: https://twitter.com/the_ethernaut
Build a Basic App with Solidity - dApp University tutorial for a solidity "to-do" client-side dapp
Simple Easy Programming - basic programming prerequisites/concepts
Verify Contract Code on Etherscan
Contracts Wizard by OpenZeppelin - interactive contract generator, based on desired standard (current support for ERC20 and ERC721) and any other parameters and desired features (token name, symbol, premint amount, access control, etc.)
Solidity Gas Optimization Tips - tips and tricks to keep gas cost low by Mudit Gupta
Solidity Bit Magic - tips on manipulating bits in Solidity and related gas optimization
Checklist for Contracts in Solidity
Secureum Epoch 0 Course - Secureum epoch 0 coursework and quizzes with linked content
Buildspace - learn and build web3 projects and earn NFTs
Blockchain Development Guide / devpill.me - a public good guide for blockchain development on Ethereum
Beginner's Guide to Yul - beginner's guide to Yul, a form of assembly language inside smart contracts
Solbase - Modern, opinionated, and gas optimized base for smart contract development by SolDAO.
OpenZeppelin Contracts - library of secure, community-vetted solidity contracts
LexDAO Assets - codebases, dApps and other assets maintained by LexDAO
Remix - Ethereum IDE with plugins and debugging
Hardhat - Ethereum IDE including local Solidity and Typescript support, debugging, and numerous plugins
Foundry - Ethereum development toolkit by Paradigm, including a Rust reimplementation of dapptools
Ethereum Dev Tools - tools, components, patterns, and platforms for developing applications on Ethereum by Consensys
OpenLaw Library - free legal agreement templates for smart contract integration via OpenLaw's markup language
Web3 Type Converter - convert from a bytes32/hex into a string/number or vice-versa
Rimble Design System - open-source library of React components, kits and guides for dApp UX design
Build Secure Contracts - Trail of Bits repo on best practices for secure smart contracts
Solidity Audit Checklist - checklist of things to look for when auditing Solidity smart contracts, by tamjid0x01
Security Review Checklist - StackExchange list based on community wiki
Solcurity - opinionated security and code quality standard for Solidity smart contracts.
Code4rena Audit Reports - code4rena audit reports including findings, code excerpts, and explanations
OpenZeppelin Audits - rundowns of past audits conducted by OpenZeppelin
Re-entrancy Attack History - documented history of re-entrancy attacks by pcaversaccio
DeFi Hack Labs - DeFi Hack reproductions, including instructions, by SunWeb3Sec
Genesis 0x01: Simplified Roadmap for Blockchain Security
Dev Blog Security Recommendations - periodic security updates from Consensys as to best practices
Slither - suite of Solidity vulnerability detectors, prints visual information about contract details, and provides an API to easily write custom analyses
Secure Dev Workflow - workflow for solidity smart contract security by Crytic
MythX Security Analysis Tool - security analysis API to create purpose-built security tools for smart contract developers
Solidify - coming soon tool from Coinbase to automatically detect and classify smart contract security risks