The Ethereum Foundation has released the Strawmap, a roadmap that plans to achieve the Lean Ethereum goal by 2029 through a phased approach via forks. H* will be the last fork not to include Lean features, I* will introduce leanVM and Lean transactions, J* will add Lean proofs, data availability sampling, and PCS, and Lean Ethereum will be complete by phase L. Lean Ethereum aims to improve performance and address the threat of quantum computing by streamlining the protocol, eliminating redundancy.
