# TypeScript This demo originally covered direct use of the `tsc` TypeScript compiler. At the time when the demo was first written, TypeScript 2.2 had a module system that was incompatible with the pure JS ecosystem. Since then, various language improvements and compiler changes have obviated this demo. Uses of TypeScript are scattered throughout other demos. [![Analytics](https://ga-beacon.appspot.com/UA-36810333-1/SheetJS/js-xlsx?pixel)](https://github.com/SheetJS/js-xlsx)