Gossamer - Go implementation of the Polkadot Host. @polkadot/apps - Portal into the Polkadot and Substrate networks. Provides a view and interaction layer from a browser. Substrate - Next-generation framework for blockchain innovation. Substrate Archive - Blockchain Indexing Engine. Run alongside a substrate-backed chain to index all Blocks, State, and Extrinsic data into PostgreSQL. Parity - Blockchain Infrastructure for the Decentralised Web. (GitHub) polkadot-launch - Simple CLI tool to launch a local Polkadot test network. Acala Network - Cross-chain DeFi hub and stablecoin based on Substrate for Polkadot and Kusama. (Web) Polkassembly - Place to discuss and vote on Kusama and Polkadot governance. (Code) Bandot - Polkadot stable coin credit system. (Code) polkadot/api - Promise and RxJS APIs around Polkadot and any Substrate-based chain RPC calls. Cumulus - Set of tools for writing Substrate-based Polkadot parachains.