Probably in that it's the language with first-class support on that platform. Adoption of the language is encouraged more by the target platform's support for i

Probably in that it's the language with first-class support on that platform. Adoption of the language is encouraged more by the target platform's support for it, than by its independent merits as a programming language. I'm not sure I'd agree though; Swift shares this position with its predecessor Objective-C. Swift's success versus Objective-C can be attributed to its relative merits as a programming language.