Solana’s Alpenglow upgrade is moving to public testnet with a target of cutting transaction finality from roughly 13 seconds to around 150 milliseconds.Alpenglow replaces TowerBFT with Votor, allowing validators to reach agreement through one or two direct voting rounds.Agave 4.3 is required for the test, while Firedancer and Frankendancer do not yet support Alpenglow.Sept. 28 is listed for tentative Agave 4.3 feature activation on mainnet, but it is not a confirmed Alpenglow launch date.