Developing Office add-in / plugin
in Visual Studio .NET - VB.NET, C#, C++

Add-in Express™
for Microsoft® Office and .net

No ad claims - facts only!

When you have a look at the marketplace of development components and tools, you will probably run into numerous vendors claiming that their products are the best. As you may well imagine, Add-in Express is no different. Before you dismiss our claims, take a moment to review the facts below and see for yourself why Add-in Express has no equal competitors on the Office development market. Of course, you may get tired of reading this rather long list. In this case draw your attention to Fact #ZERO only. This Fact will explain to you why Add-in Express was created and what it is being developed for.

Fact #1: All available Office versions are transparently supported

  • you can develop version-neutral Office plug-ins

The Add-in Express programming model, its run-time code and all Add-in Express components are version-neutral and work on Office 2000 through Office 2021/365.

Fact #2: All available Office suites are supported

  • you increase the installation base for your Office plug-ins

Add-in Express supports all Microsoft Office suites including Student, Home, Standard, Small Business, Professional, Professional Plus, Ultimate and Enterprise.

Fact #3: All Office applications are supported

  • one add-in can support all Office applications

Add-in Express supports the most popular applications from the MS Office family, including Outlook, Excel, Word, PowerPoint, Project, FrontPage, Access, Visio, Publisher, MapPoint and InfoPath. With Add-in Express you don't develop different add-ins for different applications. Each add-in / plugin based on Add-in Express is shared, and you can add or remove any applications from the supported application list at any time.

Fact #4: Low-cost and free IDEs

  • you stay with the IDE you like

Add-in Express completely supports VB.NET, C#, C++. In addition, Add-in Express supports all editions of Visual Studio, including free Visual Studio Express.

Fact #5: Command bars, menus and controls on Office 2000 - 2003

  • you use designers instead of coding

Special command bar components provide the easiest and most flexible way to create your own controls on new or existing toolbars or menu bars, to replace any built-in toolbars with your own ones, to place your controls and any built-in controls on your toolbars side by side, menus and context menus. Moreover, all command bar components and controls are compatible with the “Windows in Taskbar” mode of all Microsoft Office applications and take into account all pitfalls and features of the command bar system of all Office applications. So, you develop the add-ins GUI more quickly than ever before.

Fact #6: Ribbons, Quick Access Toolbar and Office Menu

  • you use designers instead of coding

Special components provide the easiest and most flexible way to create your own or customize any existing tabs for the Office Ribbon UI, to customize the Quick Access Toolbar and the Office Menu. No XML, no code, you use a visual designer.

Fact #7: Interception built-in controls

  • you use designers instead of coding

Using a special component you can embed your code into event handlers of the built-in controls such as the Send button in Outlook, the Save menu item in Word, the Find command in Excel, etc. In addition, you can disable standard event handlers and completely replace them with your own ones.

Fact #8: Real keyboard shortcuts in all Office applications

  • you use designers instead of coding

Add-in Express allows you to create new or override existing keyboard shortcuts and use them for your custom controls. Now with command bar components and keyboard shortcuts you can completely substitute any built-in controls with your own ones, e.g. the Save and SaveAs commands and Ctrl-S and Ctrl-Shift-S shortcuts to store Office documents in your document management system.

Fact #9: Advanced Outlook features

  • you use designers instead of coding

Add-in Express has a lot of advanced features for Outlook add-ins. Here are some of them: the support of the multi-explorer and multi-inspector modes, trusted add-ins, option pages for the main Outlook Options dialog and property pages for the Folder Properties dialog, Outlook Explorer- and Outlook Inspector-specific command bars that can be shown or enabled for selected folders only, several Outlook-specific event-helpers that help you to handle all Outlook events. Besides, you can embed your own .NET forms on Outlook Explorer and Inspector windows.

Fact #10: Advanced Excel features

  • you use designers instead of coding

With Add-in Express you can develop Excel COM add-ins as well as Excel Automation add-ins. You can build your own worksheet functions that are available in Excel formulas. In addition, Add-in Express helps you to handle any MSForms controls embedded into Excel workbooks. Now, in one project, you can combine your add-ins, custom worksheet functions and MSForms controls to build very effective Excel-based solutions. Excel RTDS projects have a special module that implements the IRTDServer interface, contains RTD topic components and centralizes your applied code. The RTD Server module has its own designer.

Fact #11: Advanced Word features

  • you use designers instead of coding

In addition to common features, Add-in Express allows you to develop Word add-ins that can handle any MSForms controls embedded into Word documents.

Fact #12: Office smart tags and smart tag modules

  • you use designers instead of coding

All smart tag projects based on Add-in Express include a special main module that implements the ISmartTagRecognizer(2) and ISmartTagAction(2) interfaces, shares one recognizer for smart tag components, centralizes all smart tags and their actions, and provides access to host application objects. With the Smart Tag module and smart tag components you can create several smart tags for one recognizer.

Fact #13: Shims and loaders: isolation and managed world over Office

  • don’t worry, it is done automatically

Shim and loader options are generated automatically when you create new solutions, and they are refreshed once your solution is changed. Forget about shims, loaders and isolation, all this is done automatically.

Fact #14: Manifests - the newest DLL hell

  • don't worry, it is done automatically

Add-in Express provides a universal manifest that supports .NET Framework 4.x. So, you can develop and debug your solution in Visual Studio 2012 - 2022.

Fact #15: Real experience in Microsoft Office development

  • you avoid tons of coding and testing

More than 60% of Add-in Express source code has been developed to overpass all pitfalls and features that different Office versions and updates have. Add-in Express is tested on all Office versions with all updates. With Add-in Express you get our practical experience in Office development.

Fact #16: Version-neutral, secure, isolated, managed, deployable and updatable Office extensions

  • you avoid tons of coding and testing

Add-in Express provides version-neutral, secure, isolated, managed, deployable and updatable Office extensions.


Add-in Express is a time-saving toolkit, and its main purpose is to give you more time to concentrate on your work instead of coding things that have already been coded many times by many people. You write your applied code only, Add-in Express implements everything else.