Cardano activated its Van Rossem hard fork on Saturday, moving the mainnet to protocol version 11, a step intended to reduce smart contract execution costs and prepare for the Ouroboros Leios scalability upgrade. The upgrade represents the first governance‑driven hard fork in Cardano’s history, distinguishing it from earlier updates that were coordinated directly by Input Output, the firm that designed the blockchain. Onchain data from Cardanoscan show the network transitioned from version 10 in epoch 643 to version 11 in epoch 644. In a weekly development report, Input Output said the upgrade includes Plutus improvements, a revised Plutus cost model, and sets the foundation for the upcoming Dijkstra era hard fork that will introduce Ouroboros Leios. Ouroboros Leios is a scaling proposal for the Ouroboros proof‑of‑stake consensus, projected to launch in late 2026 and aims to increase transactions per second while preserving security guarantees. The change marks a milestone in Cardano’s roadmap, though the full impact of the upgrade and the timing of the Leios rollout remain to be seen.