Microsoft Expression Blend is Microsoft's user interface design tool for creating rich graphical interfaces for web and desktop applications that blend the features of these two types of applications. Expression Blend is itself written using the .NET Framework 3.0 and Windows Presentation Foundation (WPF). Expression Blend is effectively an interactive, WYSIWYG front-end for designing XAML-based interfaces for WPF and Silverlight (Blend version 2.0 onwards).

Expression Blend was code-named Sparkle, and originally the product was announced as Microsoft Expression Interactive Designer, before it was renamed Expression Blend in December 2006.

Expression Blend supports the WPF text engine with advanced OpenType typography and ClearType, vector-based 2D widgets, and 3D widgets with hardware acceleration via DirectX. It is completely written using WPF, as opposed to Windows' older GDI or GDI+ graphics technologies. It is one of the applications in the Microsoft Expression Studio suite.

Availability

On January 24, 2007, Microsoft released the first public Community Technology Preview of Expression Blend as a free download on their web site. The final version was released to manufacturing along with other Expression products on 30th April, 2007. The RTM news was announced at Microsoft's MIX 07 conference for web developers and designers. Expression Blend requires .NET Framework 3.0. Expression Blend and Expression Web are also available as part of the MSDN Premium subscription. Expression Blend Service Pack 1 was released in November 2007.

A trial version of Expression Blend is available. A preview version of Expression Blend 2.0 is also available which supports developing Microsoft Silverlight browser-based Rich Internet Applications providing animation, vector graphics, interactivity and video playback capabilities.