It will be interesting to see if anyone releases an open-source port of the MS runtime to ARM... Xamarin could wind up left with only their proprietary cross-platform UI toolkit!
For iOS I think you would have to figure out how to hook up MS runtime to a LLVM AOT compiler and then do all the work Mono team did to make sure libraries compile/work without JIT.
I really hope Xamarin guys follow Microsoft lead and make entry level version of their product free. It's not just about the ~25$ per month, it's about community as well - say some guy X is maintaining .NET library Y. I write up a port/pull for Xamarin - X goes "sweet but I can't test that since I don't own Xamarin and I can't even include it in my test suite to not break it further". Now I have to maintain a branch of Y for Xamarin and most other people are likely not going to find it or willing to use it.
I don't know which % of their profit comes from the indie licensing but if it's not significant as I suspect I would hope that they see this - it will help both their adoption and the OSS community build tools for their product.
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.
For iOS I think you would have to figure out how to hook up MS runtime to a LLVM AOT compiler and then do all the work Mono team did to make sure libraries compile/work without JIT.
I really hope Xamarin guys follow Microsoft lead and make entry level version of their product free. It's not just about the ~25$ per month, it's about community as well - say some guy X is maintaining .NET library Y. I write up a port/pull for Xamarin - X goes "sweet but I can't test that since I don't own Xamarin and I can't even include it in my test suite to not break it further". Now I have to maintain a branch of Y for Xamarin and most other people are likely not going to find it or willing to use it.
I don't know which % of their profit comes from the indie licensing but if it's not significant as I suspect I would hope that they see this - it will help both their adoption and the OSS community build tools for their product.