Polkadot

Polkadot was launched in 2020. The FAQ states that "Polkadot is a work in progress. The following FAQs will continue to be updated as the Polkadot platform evolves." However, it does not provide an exact launch date.

Polkadot uses a "Parachain" architecture, which allows parallel processing of transactions across multiple connected blockchains. This is different from the single-chain approach of many other blockchain platforms. Polkadot supports cross-chain communication through its "XCMA" (Cross-Chain Message Passing) technology, allowing data and assets to be transferred between connected blockchains. Polkadot has a "sharded" design, with multiple "Parachains" operating in parallel to improve scalability and throughput compared to single-chain architectures.

Polkadot can connect multiple blockchains through its unique architecture, which includes a central relay chain and various parachains (parallel blockchains). Specifically, Polkadot allows for the connection of up to 100 parachains at a time, although this number can be increased as the network evolves and more resources are allocated. The ability to connect multiple chains is one of Polkadot's key features, enabling interoperability and the sharing of information between different blockchains, which can improve scalability and functionality across the ecosystem.