.NET is a Microsoft framework launched in 2000 designed for running applications developed in various programming languages, offering objectives such as cross-language integration and support for Windows and web applications. ASP.NET, part of this framework, enables the creation of dynamic, interactive web pages, building on technologies like Active Server Pages while leveraging compiled code for improved performance. Visual Studio 2008 serves as the integrated development environment for .NET applications, providing tools for easy programming and project management.