Add‑in Express™ for Microsoft® Office and VSTO is an extension for Microsoft Visual Studio Tools for Office (VSTO) designed to simplify and accelerate the development of application‑level add‑ins for Microsoft Outlook, Excel, Word, PowerPoint, InfoPath, and Visio. Written in Visual C#, it supports both C# and VB.NET within VSTO 2005 SE, VSTO 2008, and VSTO 2010. The primary purpose of Add‑in Express for VSTO is to enable developers to build powerful Microsoft Office‑based plug‑ins with significantly less manual coding by providing Office‑specific components, visual designers, and an optimized RAD‑based development environment.

Features

• Visual designers replacing routine coding
  • Design‑time support for custom Ribbon tabs, Office menu, Quick Access Toolbar, command bars, context menus, and menu items.
  • Add Microsoft Outlook options pages and folder property pages at design time.
  • Trap and override any built‑in Office controls on toolbars and ribbons.
  • Version‑independent event processing.
  • Context‑sensitive binding of toolbars and individual controls.
  • Determine keyboard shortcut processing at design time.
  • Add Action Panes (Excel/Word 2003) and custom Task Panes (Office 2007/2010) visually.
• Component‑centric programming model
• Add‑in Express structures VSTO development around Office‑specific components. Developers use these components and designers to create toolbars, connect to existing controls, customize Ribbon UI elements, and extend application functionality in a unified manner.
• Full support for classic GUI (Office 2003) and Ribbon UI (Office 2007/2010)
  • Customize Office 2003 menus and toolbars.
  • Add custom Ribbon tabs and modify the Office Menu and Quick Access Toolbar in Office 2007/2010.
• Use any .NET controls on Office toolbars
• Place .NET controls such as date pickers, grids, lists, treeviews, and more onto Office 2003 toolbars and Outlook 2007 toolbars for enhanced UI flexibility.
• Advanced Microsoft Outlook features
• Add‑in Express offers advanced Outlook‑specific components such as Outlook Regions (view/form), property pages, Navigation Pane shortcuts, and event helpers for Folders, Items, and Item objects. Developers can fully customize Outlook views and forms using .NET controls.
• Custom task panes, action panes, and keyboard shortcuts
• Centralized pane management simplifies creating and binding custom panes to Office apps. Developers can override default keyboard shortcuts like Ctrl+S and Ctrl+Shift+S.
• Security and deployment integration
• The framework integrates seamlessly with VSTO’s security and deployment models, setup projects, and the Visual Studio IDE.
• True RAD experience
• Following the Rapid Application Development paradigm, Add‑in Express allows developers to focus on applied logic instead of boilerplate Office integration code, dramatically speeding up the development cycle.

Benefits

• Faster development with less coding.
• Rich, enterprise‑grade Office UI customization.
• Centralized component‑driven architecture.
• Enhanced Outlook development capabilities.
• Reliable deployment and security integration.
• Full support for both classic and Ribbon Office interfaces.
• Simplified creation of panes, shortcuts, and custom UI elements.