Expression Studio is comprised of: Expression Web, Expression Blend, SketchFlow, Expression Design, and Expression Encoder.
Expression® Web enables you to produce high-quality, standards-based Websites with built-in support for today’s Web standards, sophisticated CSS design capabilities, and visual diagnostic tools.
Expression Blend enables you to mix design elements such as video, vector art, high-quality text, animation, pixel images, and 3D content with a full toolbox of advanced controls and containers to create engaging, cinematic user interfaces.
SketchFlow, part of Expression Blend, lets you quickly map the flow of an application user interface, the layout of individual screens, and even define how an application will transition from one state to another. Use the interactive review capabilities to easily share prototypes with stakeholders and collect feedback.
Expression® Design allows you to leverage existing artwork, or quickly build sophisticated vector assets with intuitive and flexible drawing tools.
Expression® Encoder, with its approachable user interface, enables designers, editors, and producers to generate gorgeous VC-1 or H.264 encoded content wrapped in a Silverlight.
You can learn more about Expression by visiting:
http://www.microsoft.com/expression/ and
http://expression.microsoft.com.