Too Long; Didn't Read
<a href="https://www.parity.io/substrate/">Parity Substrate</a> is a blockchain development framework with many cool features like upgradable blockchains, modular architecture, customizable block execution logic, and hot-swappable consensus. For an overview of the Substrate framework, watch <a href="https://www.youtube.com/watch?v=0IoUZdDi5Is">this talk from Dr. Gavin Wood</a> (Web3 Summit, October 2018).