How Expression Web is different from the Visual Studio / Visual Web Developer?
Should I use VS or Expression?
Why are they different?
Primary difference is in a set of tools provided in each product. Visual Studio and VWD come with full set of code tools that always have been part of the Visual Studio: compilers, code intellisense, debugger, class libraries, testing tools, etc. On the other hand, Expression has different design surface with more advanced CSS and visual layout tools, Direct Style Application, imaging tools, spell checker, site management with link fixup and more. Expression Web also has better integration with other Expression family products, such as Graphics Designer. However, Expression does not have debugger, it does not provide C#/VB code intellisense and neither it comes with build or test tools.
Expression is geared towards 'designer' or a person who is primarily working on a look and fell of the site: layout, fonts, colors, styles, transitions, animations. 'Developer' is a person primarily working with code, databases, business logic, i.e. spending more time in code tools. In car manufacturing terms think someone designing car extenor and interior look vs. someone who is working on engine, transmission and suspension. Some people do both kinds of work, and they can use VS/VWD and Expression Web together. Both products can exchange freely pages and both tools can open same Web sites. If you are working alone, you probably want to have both tools.
There are some similarities between VS and Expression and there are some differences. Expression uses the same code infrastructure as Visual Studio to support ASP.NET controls in the designer. It also employs Visual Studio components to provide markup intellisense for ASP.NET controls. In fact, Visual Web Developer editor team provided a lot of code that enables ASP.NET controls in Expression and lets Expression to use same validation and intellisense engine as ships in VS and VWD.
Expression, however, uses new design surface that is based on former FrontPage technologies, but is significantly improved comparing to FrontPage 2003 and provides much better CSS compliance and significantly better CSS layout tools. At the same time Expression is not based on Visual Studio IDE and hence is not able to leverage services available in the VS like debugger, compiler or code intellisense.
I am sure the next logical question is: will Visual Studio and Visual Web Developer get the same design surface in the future? Obviously, yes. We are constantly improving Visual Studio and obviously want different Microsoft products to be consistent and work together seamlessly. Visual Studio Orcas will be getting some of the functionality that is available in Expression. Stay tuned and don't miss Visual Studio Orcas Beta 1 🙂