Key tools include Circom for writing zk circuits, SnarkJS for generating and verifying proofs, Semaphore for anonymous voting and credentials, and Zokrates for zkSNARK implementation. Polygon ID offers SDKs for zk tech developmenthttps://www.blockchainappfactory.com/zk-tech-development identity. StarkEx and zkSync provide full-stack zk scalability solutions. Developers use these tools to create privacy-preserving Web3 applications from airdrops to voting to DeFi and enhance both security and UX.