Microsoft has just had its JavaScript library WinJS placed under an open source license. WinJS, a JavaScript library that enables a native-quality experience in Windows Runtime apps using familiar web technologies like HTML, CSS, and JavaScript, is now licensed under Apache 2.0.

Now that the library is open source, Microsoft plans that developers can use it to create web applications for other browsers and platforms, including Android and iOS. This feature would help developers gain time by eliminating the need to program the same application multiple times for non-Windows platforms, and browsers other than Internet Explorer, according to the company.

“The source code of the Windows Library for JavaScript (WinJS) is being released under the Apache 2.0 license as an Open Source project by Microsoft Open Technologies (MS Open Tech). The source code is available now on GitHub where you are welcome and we encourage you to try it out, provide feedback, and submit contributions,” Microsoft stated in an official blog post today.

While the name may imply that WinJS is a Microsoft version of JavaScript, it is actually a collection of tools that allow advanced JavaScript interface controls and components, minimizing the changes needed to use features across different teams. Microsoft released this library in 2011 to enable developers to create Windows applications for both Windows Phone and as new interfaces for Windows 8 using JavaScript with HTML, CSS and other development tools. It was one of the two ways that Microsoft offered to build interfaces for the new platform, the other being XAML.

The library contains components that can help build the infrastructure of a web application, such as data binding. It also offers advanced controls and interface designs as ListView, FlipView, animations and semantic zoom. Microsoft also provides several other features, along with the implementation code, on their website.

“The community is welcome to provide feedback on the check-ins, bug fixes, and new features through GitHub. You can build and test products on a daily basis using the most up-to-date version of the source code and corresponding tests. You can request bug fixes and new features by filing bugs. You can also submit pull requests for your contributions, all through GitHub. Your involvement can impact the quality and direction of the project significantly,” Microsoft explained.

At this year Build developer conference, Microsoft focused on cross-platform apps where the company believes developers to create universal apps not only for Windows, but for Windows Phone and Xbox One.

Extending WinJS to other browsers and devices beyond Windows, Microsoft intends to further extend that reach and allows developers to bring the personality of Windows apps to the web without rewriting code or learning new skills. It also shows that the company would like to see more Windows 8 and Windows Phone 8 apps made with the toolkit instead of XAML. It will be interesting to see if more developers decide to jump in and start using WinJS for their apps.

The library is now under the care of Microsoft Open Technologies and the code is on GitHub.