Visual Studio .NET is a rather expensive software program that is available in several different editions.  The most expensive edition is the .NET Enterprise Architect.  For full details, visit the Visual Studio page of Microsoft's web site. 

If you'd like, you can try Visual Studio on line, for free for three hours. 

Visual Studio is NOT required to use .NET technology.  You take take advantage of .NET technology with other tools such as Dreamweaver MX, or if you happen to be a coding guru, and you are doing a web application, you can use tools like Macromedia's Homesite, which is a code-only editor for web development. 

However, I am am involved with several professional Users Groups (Software Development Forum and Bay.NET User's Group are two of the ones in the San Francisco Bay area) and every single developer that I have worked with in these groups shares my feeling that programming in the Visual Studio environment is both enjoyable and productive.

Visual Studio is particularly attractive for:

• Working with a group of developers on a major project because it has tools that facilitate this interaction.
• Working with developers who program in various languages such as Visual Basic, C#, and COBOL.net - The program allows each developer to use the language that they prefer, and it provides a common programming environment that makes it easier for a coding guru to look at the various projects and "solutions" and suggest improvements to the developers.
• Learning the .NET environment because it has a host of features, such as intellisense, which simplify the task of learning the extensive .NET class library and writing code.
• Building web applications that need to be used by desktop machines and wireless devices because several prototype sites that were built for developers, such as the ibuyspy site, offer code bases that can be quickly adapted
• Developing and deploying to Portable PCs because software development kits that feature emulators are available.
• Any developer who needs to debug an application quickly, because it offers a very extensive debugger.

Visual Studio is provided with a subscription to MSDN.