[slaven]

It's amazing that Apple managed to go from hatching the idea in mid-2010 to releasing a fully working framework 4 years later, with tight IDE integration, huge amount of testing and compatibility without a single leak (that I've heard of).

[jayvanguard]

No doubt. Also amazing is that they promoted a compiler architect to eventually lead the whole tools group. This is good news.

[gilgoomesh]

The existence of a programming language named Swift under internal development at Apple had leaked. What it was for wasn't clear – it certainly wasn't clear that it would replace Objective-C.

[kgarten]

can you give a reference?

[ralfd]

Source? There is no mention on Macrumors on "Swift" before June 2.

[sampo]

http://www.reddit.com/r/swift was actually made 6 months ago.

[chc]

Doesn't it use the same frameworks as Objective-C?

[SoftwareMaven]

It does (direct interop with ObjC was obviously a design constraint; just look at function signatures), but there was still a tremendous amount of work to make a language one guy started on in 2010 into a beta today.

[smackfu]

It's not clear how much code is actually written in Swift so far, so I'm not sure how much testing/compatibility was required.

[eddieroger]

If they're willing to allow developers to release an app written in Swift when the beta ends, I'd say they're pretty comfortable with it in production. If Swift is really four years old already, who knows what components could be already in Swift. And it's not like Apple jumps ship overnight - iTunes spent nearly a decade as a Carbon app after introducing Cocoa.

[m0nastic]

Not that it's particularly complicated, but they mentioned yesterday that the updated version of the WWDC app (which they released right after the keynote) is written in Swift.

I don't know if that means "entirely written" or some parts, but they at least called attention to it.

[sjwright]

Which implicitly means that swift code can be compiled for iOS 7. Which isn't surprising since the compiled code uses the ObjC runtime.

[chucknelson]

When they talked about the WWDC app being written in Swift they also explicitly mentioned that Swift will run on iOS 7 and 8 as well as OS X Mavericks and Yosemite.

[lcnmrn]

Swift code compiles and runs on 10.5 and up. Tested it myself.