Designed to make life easier for the more than nine million developers who write software for iOS and Mac OS X, the firm described Swift as "Objective-C, without the C".
Swift is native to Apple's Cocoa and Cocoa Touch frameworks, on which Mac OS X applications and iOS apps respectively are built, and sees Apple looking to replace its use of the Objective C and Python languages.
However, the new language works alongside Objective-C, so developers will be able to switch between them.
Apple senior vice president of software engineering Craig Federighi unveiled Swift, saying that the new language will make coding quicker and more efficient, and that it will eliminate common programming errors.
"We have a new programming language. The language is called Swift and it totally rules," he said.
"We've used Objective-C for 20 years, and we love it. But we wondered what we could do without the baggage of C. Swift is fast, it is modern, it is designed for safety and it enables a level of interactivity in development that you've never seen before on a platform."
Apple also unveiled a feature called Xcode Playgrounds, which makes writing code interactive by instantly displaying the output of Swift code.
For developers who want more information on the new programming language, Apple is offering a free Swift guide in its iBook store, and a beta version of Swift is open now through Apple's developer programme.
Apple noted that apps written in Swift can be submitted when iOS 8 and Mac OS X 10.10 are released this autumn.
Swift wasn't Apple's only announcement aimed at developers, as the firm was keen to boast that iOS 8 arrives with over 4,000 new APIs. These include the ability for developers to bake Touch ID functionality into apps, new Camera APIs, a back-end solution called Cloudkit that helps developers eliminate the need for writing server code and new App Store features, such as the ability to offer apps in bundles.
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