问题
Since the Angular 2 team is using Typescript for it's build, would it be a feasible assumption that they could compile a version of Angular 2 that would work on older browsers?
回答1:
Edit 2:
It appears the Angular team has decided to support some non evergreen browsers. Per Brad Green (of the Angular team): What browsers versions will Angular 2 support? There's a new build widget with some hints on https://github.com/angular/angular
Currently, the Readme shows IE9 and up.
Angular 2 will only support modern browsers:
Modern browsers means the set of browsers known as ‘evergreen’ or always automatically updated to the latest version. Building for these browsers let us drop many hacks and workarounds that make AngularJS harder to use and develop on than it needs to be.
The set currently includes Chrome, FireFox, Opera, Safari, and IE10/11. On mobile, we’ll support something close to the list of Chrome on Android, iOS 6+, Windows Phone 8+ and Firefox mobile. We’re looking into supporting older versions of Android, but the jury is still out.
http://angularjs.blogspot.com/2014/03/angular-20.html
Edit: To address your comment, no Typescript is not the limiting factor for Angular 2's lack of support for non-modern browsers (nor going to provide any magical support). Typescript can transpile to ES3, so if your target browser supports ES3, you can use Typescript. Conversely, Angular 2 will gain nothing wrt supporting legacy browsers by using TypeScript.
来源：https://stackoverflow.com/questions/30669753/using-angular-2-with-older-browsers-thanks-to-typescript