The DevExpress ASP.NET Diagram (ASPxDiagram) control allows you to create custom shapes based on predefined shapes.
In this demo, the CustomShapes collection is populated with rectangle shapes (the BaseType property is set to Rectangle) that contain different texts (DefaultText). The Type property identifies custom shapes, therefore it must be specified and unique.
The SettingsToolbox property allows you to add the custom shape category to the toolbox. The DisplayMode property is set to Texts to display shape texts instead of icons in the toolbox.