[yareally]

Runtime is already open and runs on Linux, one just has to cross compile it, optimize for mobile and do the bindings and such that Xamarin already does. That's still quite a bit of legwork since Xamarin has been doing it for some years now. Not saying someone couldn't do it, but it would take a good amount of time to be on the level Xamarin is in stability and performance.

I pay for Xamarin personally and think it's well worth it if doing cross-platform compared to the alternatives out there. I'd continue to do so until there's a very stable open sourced alternative. However, I think Xamarin knows such a possibility could happen and that's why they primarily target enterprise and not individual developers.

https://github.com/dotnet/coreclr