Polkadot is the flagship protocol of the Web3 Foundation, and while Polkadot can be defined as a protocol, a network, or, a type of infrastructure, it best serves to be an ecosystem. For true decentralization, there should be multiple implementations of Polkadot. Even being a layer 0 protocol that attempts to build an interconnected, interoperable and secure Web3 ecosystem, Polkadot is a complex piece of software, and its formal implementation depends on being built on top of a tech stack.
This page will focus on implementations of Polkadot's underlying infrastructure (i.e. runtime, host).
A Wasm-based Meta Protocol
Polkadot uses WebAssembly (Wasm) as a "meta-protocol". This allows for the use of any programming language that can be interpreted or compiled into Wasm - being the driver for Polkadot's multiple implementations.
Parity Technologies: A Rustic Vision for Polkadot
Parity Technologies is often in the spotlight for its core development of Polkadot, and while this is true, Parity Polkadot also serves to be the Rust client. Parity Tech has a rustic vision for Polkadot through the use of their main product, Substrate. Substrate can also be used for different chains and different networks, but in the case of Polkadot, Substrate acts as the tech stack that is used to implement Polkadot's sharded heterogeneous multi-chain model.
Parity Tech focuses on blockchain infrastructure for the decentralised web, where they initially offered an Ethereum client (Parity Ethereum). Parity Tech was hired by the Web3 Foundation to foster the development of the first implementation of Polkadot.
Polkadot can support parachains that are not built on Substrate, In particular, as long as the state transition function (STF) of a shard is abstratced into Wasm, the validators on the network can execute the STF within a Wasm environment.
Note: chains can also be built on Substrate and are not required to be deployed onto Polkadot. More on Polkadot's architecture is available on the Architecture page.
As stated in the Soramitsu grant announcement:
It is critically important to have multiple implementations of the Polkadot protocol for a number
of reasons, including decentralization, knowledge dispersion, and better definitions of the
protocol... Multiple implementations of Polkadot improves network resilience and adds to the
decentralization of the network. The governance of the network is more democratized when multiple
teams build clients that run the nodes in the network.
ChainSafe Systems: Gossamer
Gossamer is a Go implementation being built by ChainSafe Systems, a blockchain R&D firm based in Toronto, Canada that is also building an Eth2.0 Serenity client. They were awarded a grant from the Web3 Foundation.
Kagome is a C++ implementation of the Polkadot Host being built by Soramitsu, a Japanese digital identity company that previously developed Hyperledger Iroha. They were awarded a grant from the Web3 Foundation and released the first version of Kagome in April 2020. As part of the process, they also released a libp2p networking layer in C++.
Polkadot-JS Project: Polkadot-JS
Other implementations that have received grants
While the ecosystem continues to grow rapidly, the continued development of alternative implementations will only make Polkadot stronger. Consider becoming a contributor to the ecosystem, and learn about the how you can receieve a grant for your development.