To create ASP.NET web applications, you can use Visual Studio.
Visual Studio Express for Web, a free standalone product, is part of the Visual Studio family.
It is a development environment for building, testing, and deploying web standard applications using (i) ASP.NET, (ii) Internet Information Services (IIS), (iii) SQL Server, and (iv) Windows Azure.
It develops, debugs, and deploys using the latest standards (HTML5, CSS3, and JavaScript) and all of the ASP.NET framework.
Visual Web Developer (VWD) Express (till 2012)
VWD is one of ASP.NET development tools.
Visual Web Developer Express is a free Visual Studio web development environment for building and testing next generation standards-based web applications and services.
ASP (Active Server Pages) released in 1996
ASP is an HTML page that includes one or more scripts (small embedded programs) that are processed on a Microsoft web server before the page is sent to the user.