Excel Add-in Development | Framework Criteria

Although the desktop may be slowly dying as phones, tablets, and other devices encroach; many businesses and consumers remain loyal fans and active users of Microsoft Office and Excel. According to Microsoft, there were 1.2 Billion users of Office as of March 2016.  Excel’s core capabilities include a flexible tabular data representation indexed by rows and columns, a charting module, a catalog of built-in functions, and a rich programming model using VBA.  For heavy, data intensive commercial and academic users of Excel, there is a need to extend Excel’s core capabilities with custom calculations, new data sources, real-time refresh, and embedded GUI’s.

In this series, I will be covering several topics.

• Excel Addin Framework Evaluation Criteria
• UDF
• Embedded GUI
• RTD
• Portability
• Deployment
• Troubleshooting

There are several criteria when evaluating which Excel addin framework to use.

 

Criteria	VSTO	Add-in Express	Excel DNA	PyXLL
Platform	Microsoft COM, VSTO, C/C++, .NET, VBA	.NET	.NET, VBA	Python v2.3-3.6
Price	MSDN	Commercial. $500-900/dev/yr	Free	Commercial. $100-200/dev/yr
Portability	No. PIA version dependency.	Has portability layer for O2000-2016.	Use with Net Office to support O2000-2016.	Supports O2000-2016.
Open Source	No	No	Yes	Yes
Support	Yes	Yes.	Yes	Yes
UDF	Yes. Native	Yes	Yes	Yes
Ribbon	Yes. Native	Yes	Yes	Yes
RTD	Yes. Native	Yes	Yes	Yes
GUI	Yes. Native	Yes	Yes	No
Office Breadth	Yes. Native	Supports Excel, Word, and Outlook	Only Excel	Only Excel
History	1997	1998	2005	2010

If you are looking to build an Excel product suite or family of add-ins, then I strongly encourage you to examine Add-in Express or Excel DNA.  Both are fully featured and have broad language support (unlike PyXLL), and both are much easier to use than the native Microsoft VSTO libraries.  Both have active user communities with 1000’s of developers each.  

If you intend to support other Office products such as Word or Outlook and are also not comfortable with using open source software, then choosing Add-in Express makes wise sense from a long-term maintenance, TCO perspective.  

If you are budget conscious and are developing a PoC or MVP for just Excel, then choosing Excel DNA and Net Office is a solid starting point that you can build upon.

If you intend to develop Excel add-ins which use native, platform features that are idiosyncratic to a specific version of Office (which I do NOT recommend unless it offers durable competitive advantage to your customers), then use VSTO.