Ethereum's EIP-8297, known as the Partitioned Binary Tree or PBT, went live on October 29, 2026, on the glamsterdam-pbt-1 mainnet shadowfork run by ethPandaOps. The proposal replaces Ethereum's hexary Merkle Patricia Trie with a binary tree that combines account headers, contract storage and contract code, groups related keys into designated zones, and removes RLP encoding. Besu nodes rebuilt their state from existing databases in approximately 2 hours and 41 minutes during the test. Full mainnet deployment is targeted for Q4 2026, although no activation date has been announced. PBT is designed to support smaller state proofs, stateless clients (nodes verifying blocks without full state), future state expiry and easier zero-knowledge proving without changing gas schedules or EVM operation. The main execution risk is ensuring that Ethereum's multiple client implementations convert state correctly; further shadowforks, tests involving other execution clients and a firm activation date are the next milestones.