Holešky testnet, launched by Ethereum developers on September 15, has a supply of 1.6 billion ETH, making it more accessible than the older Goerli network. The network is expected to be used for staking, infrastructure, and protocol development. Sepolia will remain the dominant network for application development. The large initial supply of Holešky testnet Ether (HETH) aims to address the low supply issue faced by Goerli testnet. The Ethereum team has been encouraging application developers to move from Goerli to Sepolia, with plans to deprecate Goerli in January 2024. Holešky will play a crucial role in testing and implementing various features before they are introduced on the mainnet.