Babel
Babel · The compiler for next generation JavaScript
Babel is a toolchain that is mainly used to convert ECMAScript 2015+ code into a backwards compatible version of JavaScript in current and older browsers or environments.
できること
Transform syntax
Polyfill features that are missing in your target environment (through @babel/polyfill)
Source code transformations (codemods)
And more! (check out these videos for inspiration)
2018年8月にTypeScriptをサポート
TypeScript and Babel 7 | TypeScript