Unless something has changed recently, VBA in Excel and other Office applications isn't .NET at all. It's basically just VB6.

When you go to edit VBA inside Excel, you get a VB6 IDE. I just tried it in Excel 2016, and it looks the same as it always has.

Their are ways to develop Office add-ins using .NET, but they aren't built in the way VBA and its IDE are.

> "Their are ways to develop Office add-ins using .NET, but they aren't built in the way VBA and its IDE are."

It's also worth noting that you can build custom tools in Office using web technologies (HTML/CSS/JS).

Also, there are also a number of options other than Excel formulas and VBA for manipulating Excel data, including DAX and M.

https://en.wikipedia.org/wiki/Data_analysis_expressions

https://msdn.microsoft.com/en-us/library/mt270258.aspx

M's syntax is kind of similar to F#/Ocaml. The only downside is the editor (very basic).

All of the above are built into Excel. If I was starting out building an Excel add on, I'd use the web technologies option.

Yeah the VBA in Excel isn't .NET at all. Which makes it even harder to take something that was VBA in excel and trying to utilize it somewhere else (e.g. a .NET add-in to Excel or using any of the Excel interops via something like C#/VB.NET)

I imagine you'd be in for some fun times with COM if you want to call that VBA code from a .NET language.

Does Excel still use the virtual machine they built in Office 6? I think it was the first whack at aligning the Mac and Windows versions. That was hard. We couldn't afford to give everyone more than 8MB of DRAM.