The 1.0 beta release of Substrate.
This introduces our draft "final" 1.0 API for building Substrate-based blockchains and is what our documentation efforts will target.
It includes GRANDPA (AfG/SHAFT) finality as well as Aura block production. It has the latest governance protocols including lock-voting and delayed-enactment. It includes the latest tagged, pluggable transaction queue and the latest "wasm" smart-contract environment module. There are also various updates to networking and other lower-level infrastructure.