Expression Blend is an interactive design tool for creating XAML-based interfaces for WPF and Silverlight applications. It features visual design tools like behaviors, visual state manager, and transitions. Silverlight is for rich browser apps while WPF is for desktop apps. The interface is similar to Photoshop with design and code views. Common containers include grids, canvases, stack panels, and dock panels. Other controls include listboxes, trees, expanders, and data grids.