Microsoft open sources its tool for porting iOS apps to Windows

When Microsoft revealed its plans to port Android and iOS apps to Windows, it was a bombshell that few expected. Now Microsoft has taken an early build of its development environment for iOS, known as the Windows Bridge, and released it to open source.

Windows Bridge, also known as Project Islandwood, is scheduled to release this fall, in conjunction with new capabilities that Microsoft will release to its Visual Studio development environment. But for now, Microsoft is pushing the technology into the open-source community via GitHub.

Although the history of the personal computer is implicitly tied to Microsoft, the Windows app environment (outside of desktop PC games) has struggled as developers have turned to more successful mobile platforms, such as iOS and Android. Microsoft’s development efforts have been designed to make it easy for Android and iOS developers to take their apps and port them to the Windows platform.

Microsoft actually has a total of three versions of the Windows Bridge in development. “Project Astoria,” the development environment to port Android apps to Windows, is in an invitation-only technical preview and should be released in a public beta this fall. “Project Centennial,” a bid to port existing Win32 Windows apps to the Windows Store and Windows 10, will enter public testing next year.

The Project Islandwood iOS bridge supports both Windows 8.1 and Windows 10 apps built for x86 and x64 processor architectures. Soon, Microsoft will add compiler optimizations and support for ARM, which will add mobile support, Microsoft’s Kevin Gallo said in a blog post.

Why this matters: According to Statista, in July Android users were able to choose between 1.6 million apps in the Google Play Store. Apple’s App Store remained the second-largest app store with 1.5 million available apps. Microsoft hasn’t publicly disclosed how many apps it has in the Windows Store of late, but it’s almost sure to be fewer than 300,000. Granted, Microsoft needs to solve its app store problem by weeding out “crap apps” as well as increasing the overall number. Inviting leading Android and iOS developers to port over their more popular apps helps Microsoft tackle both challenges simultaneously.