The VS 2005 Web Application Project option provides an alternate web project model option to the VS 2005 Web Site Project Model that ships built-into VS 2005.  VS 2005 Web Application Projects support the same project, build and compilation semantics as the VS 2003 web project model.  Specifically:

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  All files contained within the project are defined within a project file (as well as the assembly references and other project meta-data settings).  Files under the web’s file-system root that are not defined in the project file are not considered part of the web project.

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  All code files within the project are compiled into a single assembly that is built and persisted in the \bin directory on each compile.  Incremental publishing of compiled apps is fully supported within the IDE (see this post for details).

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  The compilation system uses a standard MSBuild based compilation process.  This can be extended and customized using MSBuild extensibility rules.  You can control the build through the property pages, name the output assembly or add pre- and post-build action rules.  It can also provide much faster compile times for large web projects.

Because the VS 2005 Web Application Project model has the same conceptual semantics as the VS 2003 Web Project Model, it also makes migrating VS 2003 web projects very, very easy – with zero/minimal code changes required.  To learn how to automatically upgrade a VS 2003 web project using this option, please review these VB and C# tutorials that walkthrough the VS 2003 to VS 2005 upgrade process step-by-step.

If you want to migrate an existing VS 2005 Web Site Project to be a VS 2005 Web Application Project, please also review these other VB and C# migration tutorials that walkthrough the Web Site to Web Application conversion process step-by-step.  This article here also describes some of the differences between the VS 2005 Web Site Project Model and VS 2005 Web Application Project Model.

Note that the VS 2005 Web Application Project option is available now as a free web download.  It will also be added built-in to VS 2005 SP1, and will be fully supported with Visual Studio releases going forward.  

Read More at Scott Guthrie’s Blog