An appchain is a dedicated blockchain built for a single product or ecosystem. Instead of competing for blockspace alongside thousands of unrelated apps, companies can spin up their own execution layer—usually secured by Ethereum. Today, most appchains are built on Ethereum Layer‑2s, combining Ethereum’s security with faster, cheaper transactions. Frameworks like Arbitrum Orbit and Optimism’s OP Stack make launching one nearly plug-and-play. Appchains are especially compelling for platforms a...