Solana activated its Alpenglow consensus upgrade on mainnet-beta on October 21, 2026, replacing TowerBFT at slot 459,653,000

From the articleSolana Activates Alpenglow on Mainnet, Swapping Out TowerBFT for a Faster Consensus Engine - UnchainedAlso in Anza's Alpenglow goes live on Solana, cutting finality to 150 milliseconds, Solana Alpenglow Goes Live in 'Most Ambitious' Upgrade Since Ethereum's Merge - Decrypt, Solana’s Alpenglow Launches on Mainnet, Targets 99% Faster Finality