Apple, a company with a less than stellar record of engagement with open source, has made good on promises to turn Swift, a programming language for desktop and mobile devices, into an open source project.

Apple unveiled Swift in June 2014 with the goal of making it easier for programmers to write apps for OS X, iOS and other Apple platforms. The company says the language is “powerful and intuitive” while also making it easier for programmers to find and fix errors in their code.

Swift was originally proprietary, with promises from Apple that it would eventually be open-sourced. On Dec. 3, the company delivered on that promise by releasing Swift under the open source Apache 2.0 license.

The change means developers are now free to adapt Swift for use on platforms other than Apple’s. In the future, Swift could become a popular programming language for Windows and Linux-based operating systems — and, by extension, porting apps written in Swift for iOS or OS X to other environments may also become easier.

That’s a big deal, as there are currently few programmer-friendly languages that offer ready cross-compatibility between all the major desktop and mobile platforms.

The news is also significant given that Apple has a less than stellar history of playing nicely with the open source community. The company has readily integrated open source code into its own products, and it has sometimes contributed its work back to the open source projects on which it draws, yet Apple’s own products tend to be as proprietary as proprietary can be.

That the company is taking a different approach with Swift should be encouraging for the open source community — especially at a time when Microsoft, the other age-old foe of open source, also appears to be in the process of radically reconfiguring its stance toward freely redistributable code.