Chia is a budding ecosystem designed with the security of Bitcoin and the programmability of Ethereum. It was created by Bram Cohen, founder of Bit Torrent, and took on over 300,000 nodes in the first 6 months, making it the most decentralized blockchain.
HDDs are secure and use minimal energy, and the client runs on nearly any computer, making native DApp development simple. The ecosystem is just getting started but is already supporting institutions like the World Bank and Costa Rica. Chia has all the right stuff and is poised for mainstream adoption.