The tools and technologies used to develop smart contracts include:
1. Ethereum: Ethereum is an open-source, blockchain-based platform that enables users to create and deploy decentralized applications and smart contracts. It is the most popular platform for developing smart contracts. An example of a smart contract developed on Ethereum is the CryptoKitties game.
2. Hyperledger Fabric: Hyperledger Fabric is an open-source platform for developing enterprise-grade blockchain applications and smart contracts. It is based on a modular architecture that allows organizations to customize their blockchain applications to meet their needs. An example of a smart contract developed on Hyperledger Fabric is the IBM Food Trust.
3. NEO: NEO is an open-source platform for developing digital assets and smart contracts. It is designed to provide a secure and scalable environment for developing and deploying decentralized applications. An example of a smart contract developed on NEO is the NEO Name Service.
4. Quorum: Quorum is an open-source platform for developing enterprise-grade blockchain applications and smart contracts. It is based on the Ethereum platform and provides additional features such as privacy, performance, and security. An example of a smart contract developed on Quorum is the JP Morgan Chase Payment Gateway.