Cardano’s mainnet activated the van Rossem hard fork on July 18, moving the network to Protocol Version 11.

The upgrade, the first decided through on‑chain governance, updates Plutus cost models and prepares the network for the Ouroboros Leios upgrade.

The proposal was ratified on July 13 by delegated representatives, stake pool operators and the Constitutional Committee, achieving 77.63% DRep and 52.7% SPO support.

The hard fork follows testing on Preview and Preprod networks and introduces cheaper smart‑contract operations.

Input Output said the upgrade lays the foundation for the Dijkstra era hard fork that will bring Ouroboros Leios, which aims to increase transaction throughput while preserving security.

Van Rossem marks the first Cardano hard fork executed under Voltaire on‑chain governance, replacing the earlier coordination model used by the founding development groups.

The community previously rejected a 7.8 million ADA request for the 2026 Cardano Summit, while treasury funds support ongoing work on Leios, Hydra and Mithril.

Development on Dijkstra and Leios continues, with no announced launch date, though the scaling upgrade is expected later in 2026.