- slice notation https://github.com/tc39/proposal-slice-notation - operator overloading https://github.com/tc39/proposal-operator-overloading - object pick/omit https://github.com/tc39/proposal-object-pick-or-omit - parameter decorator https://github.com/tc39/proposal-class-method-parameter-decorators - structs and mutexes https://github.com/tc39/proposal-structs - Intl.MessageFormat https://github.com/tc39/proposal-intl-messageformat