Stacks is a layer-1 blockchain that connects to Bitcoin for security and enables decentralized apps and predictable smart contracts using the Clarity language. Stacks implements Proof of Transfer (PoX) mining that anchors to Bitcoin security.
Stacks is a Bitcoin layer for smart contracts, it enables decentralized apps for Bitcoin. Stacks is an open-source project with an ecosystem of independent entities including Hiro System an entity that builds developer tools for Stacks.