GeezerVison

AtScript was a proposed JavaScript-based scripting language extending Microsoft's TypeScript and transcompiling to JavaScript. It was introduced in October 2014 at the ng-Europe conference by the developers of Google's AngularJS web development framework as the language that the upcoming Angular 2.0 would be built with.^[1][2]

AtScript was originally intended to run on top of TypeScript, while including some features from Dart. In October 2014, Google announced that Angular 2.0 would be written in AtScript.^[3] In March 2015, Microsoft announced that many of AtScript's features would be implemented in the TypeScript 1.5 release, and that Angular 2.0 would be built on pure TypeScript.^[4]

The name “AtScript” comes from the @ “at” symbol used for annotations in many languages (e.g. Java annotations and Python decorators).