The Diagramming Tool app was built with Telerik HTML5 Kendo UI widgets. Telerik Kendo UI framework consists of 70+ UI widgets that take care of the common functionality of your application, while leaving you with more time to work on its business logic.
The app demonstrates the Diagram widget functionality and its integration with numerous other Telerik components. The source code is available so you can use it as a base for implementing your custom scenario.
The sample app enables users to modify, add, remove and connect shapes. Once they are happy with the diagram they have created, they can save it to a file and load it back later.
Make sure you try the various built-in layouts of the Diagram control showcased in the sample.