The Ethereum Foundation has outlined a fork-by-fork roadmap to achieve Lean Ethereum by 2029, with the H* fork set to be the last without Lean features. According to PANews, the foundation said in a post on X that I* will introduce leanVM and Lean transactions, J* will add Lean proofs, data availability sampling and PCS, and Lean Ethereum will be complete by the L stage. Lean Ethereum is a long-term protocol redesign vision for Ethereum’s second decade, aimed at simplifying the protocol and removing redundancy while preserving decentralization and security, improving performance, addressing quantum-computing threats, and rebuilding the underlying technology stack.