01
Ethereum's next big upgrade just hit its first public test network. Here is what it actually does.
02
Glamsterdam reached the Sepolia testnet on October 6, 2026, after client teams raced to patch late bugs.
03
It bundles two changes: enshrined proposer-builder separation, and Block-Level Access Lists for parallel execution.
04
Proposer-builder separation moves how blocks get built into Ethereum's own rules, instead of trusting outside relays.
05
Block-Level Access Lists let validators process unrelated transactions at the same time instead of one by one.
06
Days before the test, a core developer warned any teenager could exploit free testnet ether to stall it.
07
The attack works on the test network because test ether is free. On real Ethereum, the same move costs real money.
08
Mainnet activation has no confirmed date yet. Regular ETH holders don't need to do anything right now.