Polymer (https://www.polymer-project.org/) is a JavaScript framework for creating reusable web components (using the Web Component standard) that are encapsulated and inter-operable. They take the form of custom HTML elements. For example, the dialogs in this chapter could be made into web components. To use them in a page, we would use the tags <DialogConfirm> and <DialogWordCount>, which would avoid a set of nested div elements. Polymer.dart is the Dart version of the framework and is available from pub.

Angular (https://angularjs.org/) is a framework for dynamic data views and is a giant in the JavaScript world. Again, there is a Dart version, called Angular.dart. The forthcoming Angular 2 will be written in Typescript and will support both JavaScript and Dart.