It is a visual tool for developing COM Add-ins, Smart Tags and RTD on .NET. Add-in Express implements everything required by the supported technologies such as IDTExtensibility2,ISmartTag and ISmartTagTopic, you write functional code only. It supports all main Office apps: Outlook, Excel, Word, PowerPoint, Visio, Project, MapPoint, Publisher, etc. It is developed for VB.NET, C++, C#, J# and Delphi .NET. Read more on http://www.add-in-express.com