Microsoft announced some huge news at its Build developers conference earlier this year, revealing that Windows 10 can run reworked Android and iOS apps. While developers were intrigued by the news back in April, Microsoft has kept the tools under wraps until today. In yet another surprise move, Microsoft is open sourcing its key porting tool for iOS to Windows apps. Previously codenamed Project Islandwood, the Windows Bridge for iOS enters preview today and all the source code is available immediately on GitHub.

Preview today, full release in the fall

The iOS bridge allows developers to create both Windows 8.1 and Windows 10 apps, with plans to add support for mobile later in the year. This first release is strictly a preview, so it's not final and Microsoft is really leaning on the open-source community to contribute code, testing, bug reports, and comments on where the company is heading with its porting tool. Microsoft is aiming to release the Windows Bridge for iOS broadly in the fall, alongside a public beta of the Windows Bridge for Android. Microsoft's Android bridge is currently available as a technical preview by invitation only, and Microsoft is planning to get those on the waitlist access by the end of the month.

Both the tools are designed to make it easier for developers to bring their existing Android and iOS code to universal Windows apps. While the Android version is limited to just phone apps, the iOS equivalent will allow developers to create apps that span across PCs, tablets, and phones. It's still too early to say whether these porting tools will make a big dent on Microsoft's lack of apps for Windows tablets and phones, it's a significant step to open source the iOS version to let the community decide on the direction of Microsoft's app porting tool.