We need to thank Miguel de Icaza and his personal fools’ errand for that.
Indeed, Unity is the most promising platform for cross-platform development. I have used it for pro simulations and AR stuff and I was frankly impressed with the tools and the portability. The only issue I have, me personally, with it is that it you need to swim against the current to implement true and tested best practices that allow projects to scale up while still being maintainable. Also a PBAKC issue, I think :)