C# has been standardized by ECMA & ISO since early 2000, made open source (I'm a F/LOSS user) by Microsoft, & runs on GNU/Linux platform via Mono implementation. .NET, ASP.NET MVC, Web API, and Web Pages have just been released as open source too. This gives C# and .NET platform a wider area to develop applications (giving a challenge to Java supremacy). Swift is relatively new language but intended as replacement for Objective-C, the language used for Apple's OS X & iOS (the future ahead is huge, right?) The development tools are hardly accessible since one will have to work on OS X and are often expensive, but sooner or later non-OS X/iOS developers would enjoy the same as the language itself is open source. It's inevitable to learn things like HTML, CSS, JavaScript/jQuery since they are standards. So if both, that's too much. What do you think?
Yet another way of taking notes!