A variety of platforms and networks comprise today’s blockchain landscape. Some are fully developed while others are emerging. Some adhere strictly to the blockchain standard while others deviate from the standard and are considered blockchain alternatives. Several other platforms employ distributed ledgers without the use of blockchain.
As a result, not all blockchains are created equal. Based on the capabilities built into a given blockchain platform, a variety of network types can be provisioned. These blockchain network types can be defined as public, private, consortium, federated, hybrid or semi-private. Definitions for each network type can be found in the Terminology section.
The current blockchain landscape includes the blockchain/DLT platforms listed in this section. Each listing includes a brief description of the platform, its primary focus, and any applications or networks currently available or in development. Links to other sources have been provided for more detailed information.
To date, the following platforms are most commonly leveraged and “enterprise ready” for use in the healthcare industry.
Ethereum is an open-source, blockchain application platform developed by the Ethereum Foundation. See also the Enterprise Ethereum Alliance, focused on the use of Ethereum in enterprise applications across multiple industries including healthcare. It is a decentralized platform that runs smart contracts, which are applications that run exactly as programmed without any possibility of downtime, censorship, fraud or third-party interference. Ethereum blockchains can either be public or private. Ethereum blockchain nodes can also run in cloud environments.
IBM’s Hyperledger platform provides a variety of open-source frameworks, which guide the development of blockchain networks and applications. Hyperledger frameworks include Burrow, Fabric, Indy, Iroha and Sawtooth. Hyperledger tools include Caliper, Cello, Composer, Explorer and Quilt. 
The Hyperledger organization oversees several open-source blockchain platform projects. One of the most popular frameworks is described below.
- Hyperledger Fabric, initially contributed by Digital Asset and IBM, is an open-source blockchain framework implementation and one of the Hyperledger projects hosted by The Linux Foundation. The Linux Foundation includes leaders in finance, banking, IoT, supply chain, manufacturing and technology. Intended as a foundation for developing applications or solutions with a modular architecture, Hyperledger Fabric enables components, such as consensus and membership services, to be plug-and-play.
R3 Corda is a blockchain for business enterprise application. Initially focused on financial services, it now supports business enterprise applications across multiple industries including healthcare. On December 6, 2017, Amazon Web Services (AWS) announced a partnership with R3 to allow the company's Corda platform to become one of the first ever distributed ledger technology solutions on the AWS. Corda allows users to deploy DApps onto the AWS platform and to create new apps directly. Corda also runs on other cloud environments.
R3’s Corda open-source platform is defined by corda.com as a blockchain platform. However, other references refer to Corda as a distributed ledger that is seeking to improve upon the bitcoin deficiencies related to performance scalability and privacy. 
The networks and applications that are developing on the Corda platform include healthcare and finance. The Corda Healthcare Community is one example.