After you design a Visual Studio Tools for Office solution and set up the project files, you can begin to concentrate on implementing the code and custom user interface (UI).

When you develop a Visual Studio Tools for Office solution, you write code in a class that is named a host item. The host item is the entry point for your code, and it also provides entry points into the object model of the host application. For more information, see Office Solutions Programming Model.

The type of solution that you are creating determines which features you can use in your project. For example, you can add Windows Forms controls and extended Microsoft Office controls (named host controls) to document-level customizations, but this feature is not available to application-level add-ins. For more information about features that are specific to different types of solutions, see Programming Application-Level Add-Ins, Programming Document-Level Customizations, and Office UI Customization.

For background information to help you plan your Office solutions and procedures to help you create projects, see Designing Office Solutions.