While WinJS is not built in TypeScript, there are TypeScript bindings for it[0] bundled in the WinJS repo, so it&#x27;s easy to use from TypeScript.<p>[0]: <a href="https:&#x2F;&#x2F;github.com&#x2F;winjs&#x2F;winjs&#x2F;tree&#x2F;master&#x2F;typings" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;winjs&#x2F;winjs&#x2F;tree&#x2F;master&#x2F;typings</a>