Visual Studio Tools for Office

Microsoft Visual Studio Tools for the Microsoft Office System can help you take advantage of the productivity enhancements in the Microsoft .NET Framework version to extend applications in Microsoft Office.  

Below are links to all three versions VSTO 

Office 2013 and Office 2012 
You can extend Office 2013 and Office 2010 by using Office developer tools in Visual Studio. You can build two types of solutions: solutions that focus on web integration and solutions that target the .NET Framework and are more deeply integrated with the Office object model.

What's new for Office 2013 developers

Learn about the features and technologies of Office 2013 that are of interest to developers.

Applies to: apps for Office | apps for SharePoint | Office 2013 | Office 365 | SharePoint Foundation 2013 | SharePoint Server 2013  more