Solidity will be split into two independent directions: Classic Solidity and Core Solidity

Solidity, the Ethereum smart contract language, has announced it will split into two independent development paths: Classic Solidity and Core Solidity. While Classic Solidity, currently in production with a reliable compiler, is at version 0.80.30, the team considers the language itself to be unstable (as evidenced by the 0.x versioning). Major updates will continue to be released regularly. Core Solidity is a radically reimagined Solidity with a completely rebuilt type system that supports features such as generics, first-class functions, and algebraic data types. Currently in the prototype stage, the release of Solidity 1.0 will mark Core Solidity as stable enough to become the default frontend.