Dojo Toolkit is a comprehensive JavaScript-based toolkit that provides language utilities, UI components, and various modules for web application development. It offers functionalities such as Ajax, DOM manipulation, class-type programming, events, promises, data stores, drag-and-drop, and internationalization libraries. The toolkit is used by companies like Cisco, JP Morgan, Intuit, ADP, FannieMae, Marriott, VMware, Philips, IBM, and Pearson. It also offers commercial support and training tutorials. Dojo Toolkit is compatible with HTML5, Android, iOS, Windows, BlackberryOS, and other platforms, allowing users to create robust desktop and mobile web applications. Additionally, it enables access to local devices and supports the development of large-packaged enterprise applications.