At Build 2015, Microsoft announced that they had designed tools that would make it easy for developers to port iOS and Android apps across to Windows. These tools were initially released to developers through an invite system, but now Microsoft has decided to release one set to the public as an open source project.

Project Islandwood, officially known as Windows Bridge for iOS, is now available as an open source project preview that developers can download right now through GitHub. Microsoft says the tools aren't quite complete yet, though they are targeting a fall release for the final version.

Windows Bridge for iOS includes "fairly broad" support for iOS APIs, and includes a compiler that takes Objective-C code and attempts to create a native Universal Windows app. The tool isn't perfect, and developers might need to do some tweaking to the code to get it to run correctly on Windows, but it makes porting an iOS app over to Windows much easier than developing from the ground up.

Microsoft's equivalent tool for porting Android apps to Windows, known as 'Project Astoria' or Windows Bridge for Android, will be released as a public beta sometime in the fall. In the meantime, Microsoft is hoping to give everyone on the invite-only waitlist access by the end of August.

There are two other tools Microsoft has up their sleeves that make developing Windows Store apps easy. 'Project Centennial', arriving in 2016, gives developers an easy way to port existing Win32 apps to Windows Store equivalents. 'Project Westminster' is for porting web apps to Windows apps, and that tool is already available.