One of the key TypeScript features is not only the fact that JavaScript program is TypeScript programs but also ability to add type annotations to existing java

One of the key TypeScript features is not only the fact that JavaScript program is TypeScript programs but also ability to add type annotations to existing javascript libraries without changing of their source code. For example, see port of Backbone's TodoMVC: http://typescript.codeplex.com/SourceControl/changeset/view/d397c54a55db#samples%2ftodomvc%2fjs%2ftodos.ts http://typescript.codeplex.com/SourceControl/changeset/view/...