Hi wsih, thanks! There is a lot to unpack on those threads but of the top of my head: 1. Clear separation between UX/backend Done by design in IronCalc. It is first a spreadsheet engine.

2. Multi language support, language connectivity, enhanced data types, ...

You might very well be right, but out first step is to be as close to Excel as possible. We are ~ 1 year away from being formula compatible in a reasonable way. Once we are there we can do better in different directions. I think strict typing might be very beneficial for spreadsheets engines. Anything you can do to reduce errors and human mistakes.

I strongly believe that having a competitive spreadsheet engine fully open source might be a good first step in extending and improving Excel.

Let's see!