Microsoft Expression Web, initially code-named Quartz,, is a WYSIWYG-HTML editing program for general website design and development created by Microsoft.
Expression Web replaced Microsoft FrontPage, but still offers some internal support for FrontPage users. Expression Web is part of the Expression Studio suite, but can be and is often purchased by itself.
Expression Web allows authoring of web pages integrating XML, CSS, ASP.NET, XHTML, PHP, Java Script (JSP) and Dynamic Web Templates (DWT) into sites. Sites built with Expression Web can run on Linux or Windows servers. The second version, Expression Web 2, has full native support for PHP and Silverlight. Editing classic ASP is supported but not on the same page with ASP.NET and there is no classic ASP IntelliSense support. Expression Web uses its own standards-based rendering engine, different from Internet Explorer's Trident engine.
Microsoft Expression Web provides the ability to install add-ins from third-party developers, extending the capabilities of Expression Web, but the range of add-ons is limited.
The first version of Expression Web was released on December 22, 2006.
The price of Expression Web, especially earlier versions, is volatile.
For instance, the suggested retail price for the full version of Expression Web 2 was initially $299 but then dropped to $46 in 2010 and is now $115.
Currently, Expression Web 3 is $98 for the full version and $49 for the upgrade.
Expression Web 4 was released in June 2010 and if you purchased Expression Web 3, we understand you can upgrade to version 4 for free.
By way of contrast, the main competitor to Expression Web is Adobe's Dreamweaver CS5, which retails for $380.
adapted from: wikipedia