The .NET 5+ code is very interesting!

[rgwood]

Hi there,

I happened to be reading through the Excel-DNA source code to learn more about XLL addins and hosting .NET inside Excel. I noticed a fascinating comment:

    // STEP 2: Initialize and start the .NET Core runtime

It looks like this was first introduced with a commit named "Add .NET 5+ host project". At this point my mind was blown 🤯. My understanding was that multiple CLR versions can't coexist in the same process and .NET Core add-ins are effectively impractical as a result... but maybe you found a way around that?

So, a few questions:

1. Am I correct in understanding that this code should enable Excel-DNA add-ins written in .NET Core/5+?
2. Would these add-ins clash with VSTO add-ins running on .NET Framework?
3. Roughly how far along is the .NET 5 code? Are there any major known issues, or work that you're looking for assistance with?

I'm mostly just curious at this point, I have no expectations of being able to use this anytime soon. It sounds like you're doing something really cool that I previously thought was impossible, and I'd love to learn more about it.

P.S. Thanks for publishing the Excel-DNA code. It's a great learning resource (I found it much easier to follow than Microsoft's ancient XLL templates).

[rgwood]

Looks like @govert has already answered question #2:

My understanding and experience so far is that .NET Framework 4.x can be loaded at the same time as .NET 5, and that this is in fact a supported scenario.

Very cool.