What is iSwift?
OK, that's an easy one: an Objective-C to Swift converter.
Because every Mac or iOS developer has loads of existing Objective-C libraries and code, and the only way to fully integrate your existing code with the new language is to actually re-write it in Swift. But why do it manually?
Who's behind this?
Well... if you're looking for Apple or some huge company, I'll disappoint you.
iSwift is the work of a single developer (usually going by the name of "Dr.Kameleon"), who - playing all his life with compilers, parsers, other ultra-geeky stuff and even his own programming language - cannot (obviously) say 'no' to a challenge like this one. So here you are...
Is this complete?
Well, long story short: no. But it's definitely aiming to be as complete as humanly possible.
Is it "working"?
Of course. Just don't expect it to convert every possible Objective-C source code you may have in mind - for now, that is. The whole undertaking is challenging but code-wise everything is possible. And the more it advances, the more... weird stuff it's going to pick up and successfully convert into beautiful Swift code.
May I contribute?
The fuel behind every code project is its users. If you are a coder and want to contribute, iSwift's code is (for now) closed source. However: you're very welcome to freely contribute ideas, suggestions, bug reports, anything. Something tells me iSwift's developer will greatly appreciate it. ;-)
Also, do not forget that iSwift is on IndieGoGo.