Add‑in Express™ for Microsoft® Office and .NET is a comprehensive framework that simplifies and accelerates the development of Office extensions, enabling developers to build powerful COM add‑ins, custom task panes, Office ribbons, and advanced integrations for Outlook, Excel, Word, PowerPoint, and other Office applications. Designed specifically for .NET developers, the platform unifies all Office‑related technologies into a single, coherent programming model, allowing teams to avoid low‑level COM complexities and focus on functionality. By automating boilerplate code and providing a visual designer for Ribbon UI, toolbars, panes, Outlook forms, and advanced event handling, Add‑in Express makes it significantly easier to create professional‑grade Office extensions. Developers can target multiple Office versions, integrate with multiple applications at once, and deploy add‑ins using a robust installer built into the framework.

Features and Benefits

Microsoft Office extensibility

Add-in Express is completely based on the Office extensibility technology and extends it with unique features, which makes your Office development fast, easy and effective. You can develop all kinds of Office extensions including COM add-ins, smart tags, Excel RTD servers, Automation add-ins and XLLs. Learn more…

Version-neutrality

Add-in Express provides you with version-neutral run-time, so you needn't write code for each Office version. Your write your code once, and it runs on all versions, from 2000 to 365. Moreover, your solutions are fully compatible with all Office editions, from Student and Home to Enterprise and Ultimate. Learn more…

Effective project architecture

Add-in Express generates ready-to-use solution templates that accumulated our long-term experience in Office development and deployment. The Add-in Express architecture makes your Office extensions secure, isolated, managed, deployable and updatable with your minimal efforts. Learn more…

Visual designers instead of coding

You use visual designers to customize Office menus, toolbars, ribbons, task panes, forms, windows, regions, option and property pages, etc. Add-in Express facilitates true Rapid Application Development (RAD), where you use components and visual designers instead of routine writing of glue code. Learn more…

Outlook is the premium platform

Outlook developers benefit from plenty of Outlook-related features. Using Add-in Express components and their visual designers you can create custom Outlook menus, toolbars and ribbons; make certain controls context sensitive, bind them to specified folders or content types, build option and folder property pages, add navigation pane shortcuts, embed view and form regions and more. Learn more…

1st-class GUI with Advanced Outlook Regions

Add-in Express gives you the Advanced Outlook Regions that are shared (you can place several forms from several add-ins into one region), version-neutral (your regions work equally well on Office 2003 - 2024), flexible (you can add regions for Outlook views, forms, To-Do bar, Navigation and Reading panes). Finally, you can create, close and move your regions at run-time. Learn more…

Any .NET controls on Office toolbars

On all versions of Outlook, Word, Excel and PowerPoint, you can add any built-in or third-party controls to Office toolbars. So, your own toolbars can host grids, tree views, list views, user controls, forms, etc. With Add-in Express you build a feature-rich GUI that your end-users will be fond of! Learn more…

Improved Excel extensions

If Excel is your target application, using Add-in Express you can create an amazing Excel addin GUI with the Advanced Office Task Panes that work for all Excel versions, effective real-time data servers with any number of RTD topics, new user-defined worksheet functions (UDFs) through Automation add-ins or Excel XLLs. Learn more…

Deployment made easy

With Add-in Express the deployment of your Office projects becomes so easy that you will forget about it. Each Add-in Express solution contains a setup project with all necessary prerequisites. Plus, your solutions fully support ClickOnce, so just build and publish your solution once, deploy and update anywhere. Learn more…

True RAD - you write applied code only

Add-in Express is entirely based on the Rapid Application Development (True RAD) paradigm and reduces the time you used to spend on COM add-in, smart tag and RTD server development at least by half. You write applied code only, Add-in Express does everything else.