Visual Studio 2010 Tools for Office Runtime

Visual Studio 2010 Tools for Office Runtime is a package developed by Microsoft in order to make it possible for users to run applications that have been generated by the Office Developer Tools component inside Visual Studio.
Although it was initially designed for Visual Studio 2010, Microsoft extended support for Visual Studio 2012 as well, along the development of the solution. The package has built-in support for operating systems ranging from XP and Server 2003 to the newest iterations, including Windows 8 and 8.1.
The runtime is included in the installation package of Visual Studio and Office 2010 and 2013 by default, but it can be downloaded separately and deployed easily. Please note that Office (2007 to 2013) is a compulsory dependency and so is NET Framework (either 3.5 or 4).
The installation process takes little time and requires very little efforts on the user side. The language of the system is automatically detected during the setup and used throughout the process.
However, provided that you’ll be using the runtime on installations of Windows in a language other than English, the switch to the new language should be performed automatically in most cases.
With this package installed, users will be able to launch and make use of applications that have been developed in Visual Studio 2010 with the Office Developer Tools. Most often, it is required for running add-ins and other such Office helpers and is aimed more at end users rather than developers.