In Visual Studio, a T4 text template is a mixture of text blocks and control logic that can generate a text file. The control logic is written as fragments of program code in Visual C# or Visual Basic. The generated file can be text of any kind, such as a Web page, or a resource file, or program source code in any language.
In standard Visual Studio there is no native support for editing T4 templates. Venders have created tools that support intellisense, color coding and debugging.