Q:

Apple Swift compiler for Windows

I am looking for an Apple Swift compiler for Windows (running under Windows and producing code for Windows), without having to virtualize any OS. It needs to run at least on Windows 7 x64.

A:

Silver runs on Windows and allows you to compile Swift code to Java and .NET.
Alternatively, you can compile Swift code online in a web browser on any platform, including Windows. Try:

RunSwift
SwiftStub

A:

Swift is build on the same LLVM Compiler, Objective-C is build on. (See Wikipedia)
So you need an Obj-C environment. And that is a bit complicated, but possible.
It would be much easier to build a Virtual Machine or a Hackintosh.
And as you can read from this answer, it is not a good Idea coding Obj-C (or Swift) on a PC.

A:

Swift for Windows now available on Microsoft Codeplex.
https://swiftforwindows.codeplex.com/

System Requirement 
 - Visual C++ Redistributable for Visual Studio 2015.

Or you can use official swift version on Bash On Ubuntu On Windows 10 (Anniversary Update). Checkout full step-wise guide here - Instal Swift 3.0 on Windows 10 Anniversary Update

