Hyperledger Fabric is a blockchain framework implementation and one of the Hyperledger projects hosted by The Linux Foundation. Intended as a foundation for developing applications or solutions with a modular architecture, Hyperledger Fabric allows components, such as consensus and membership services, to be plug-and-play. Hyperledger Fabric leverages container technology to host smart contracts called “chaincode” that comprise the application logic of the system. Hyperledger Fabric was initially contributed by Digital Asset and IBM, as a result of the first hackathon.
Hedera Hashgraph is a public distributed ledger for building decentralized applications. Developers can build secure, fair, blazing-fast decentralized applications on top of Hedera. The Hedera hashgraph platform provides a new form of distributed consensus; a way for people who don't know or trust each other to securely collaborate and transact online without the need for a trusted intermediary.
Cardano is more than just a cryptocurrency, however, it is a technological platform that will be capable of running financial applications currently used every day by individuals, organisations and governments all around the world. The platform is being constructed in layers, which gives the system the flexibility to be more easily maintained and allow for upgrades by way of soft forks. After the settlement layer that will run Ada is complete, a separate computing layer will be built to handle smart contracts, the digital legal agreements that will underpin future commerce and business. Cardano will also run decentralised applications, or dapps, services not controlled by any single party but instead operate on a blockchain.