Dot Net Framework

Dot Net Framework is the most Popular Framework and is used for Windows apps and Web apps and also Web Services / WCF services.

Visual Studio has a great Tooling support for developing apps and has various editions that can be used by individual developers and companies.

The framework consists of VC# / VB / VC++ Languages and many more to begin with.

There are a whole lot of books available for dot net languages and framework.