Last week, we released Windows 10 as a free upgrade in over 190 markets, taking the first big step toward upgrading 1 billion devices to Windows 10 and the Universal Windows Platform (UWP). Alongside Windows, we also delivered the Windows SDK and accompanying tools that you’ll use to build and submit Universal Windows apps. Windows 10 introduced new APIs and built a platform that does much of the work to make apps more personal through adaptive UX, natural user inputs and cloud-based services. We also introduced a series of “bridging” technologies to enable developers to bring their existing iOS, Android, Web and desktop code and skillsets to the Windows Store, for which I’ll provide an update here.

Today, we’re releasing an early look at the Windows Bridge for iOS (previously known as ‘Project Islandwood’). While the final release will happen later this fall (allowing the bridge to take advantage of new tooling capabilities that will ship with the upcoming Visual Studio 2015 Update), we are making the bridge available to the open-source community now in its current state. Between now and the fall, we’d love more eyes, feedback, and participation on the code, so we’re doing our development “in the open.”

We’re releasing the iOS bridge as an open-source project under the MIT license. Given the ambition of the project, making it easy for iOS developers to build and run apps on Windows, it is important to note that today’s release is clearly a work-in-progress — some of the features demonstrated at Build are not yet ready or still in an early state. Regardless, we’d love for the interested and curious to look at the bridge, and compare what we’re building with your app’s requirements. And, for the really ambitious, we invite you to help us by contributing to the project, as community contributors — with source code, tests, bug reports, or comments. We welcome any and all participation in building this bridge.

Salmaan Ahmed has an in-depth post on the Windows Bridge for iOS discussing the compiler, runtime, IDE integration, and what the bridge is and isn’t. Best of all, the source code for the iOS bridge is live on GitHub right now. The iOS bridge supports both Windows 8.1 and Windows 10 apps built for x86 and x64 processor architectures, and soon we will add compiler optimizations and support for ARM, which adds mobile support.

I have a few updates to report on the other bridges announced at Build as well: the Windows Bridge for web apps, ‘Project Westminster,’ is live and available with the release of Windows 10 and Visual Studio 2015. Kiril Seksenov recently wrote a blog post on the web apps bridge detailing what happens at the Windows level, how the bridge functions, how you can use it to build ‘Hosted Web Apps’ and addressing common questions.

The Windows Bridge for Android, or ‘Project Astoria’, is currently available as a technical preview by invitation only. We have been gradually inviting more developers each week and will continue to expand this preview program. Our goal is to have everyone currently on the early access waitlist in the program by the end of August; and we are aiming to release the Windows Bridge for Android as a public beta in the fall. To get on the waitlist for early access, please use the sign up form.

As we make progress on the Android bridge, we are also contributing to open-source projects used by its community. We submitted changes to help improve ANGLE. For those who haven’t hear of ANGLE, ANGLE provides translation of OpenGL to DirectX. These changes have been accepted by Google and improved ANGLE’s performance and compatibility with DX feature level 9.3.

The Windows Bridge for Classic Windows apps, ‘Project Centennial,’ that will make it possible to package and publish your current .NET and Win32-based Windows applications to the Windows Store, will be ready for public testing next year.

I encourage everyone to check out the Windows Bridge for iOS and install Windows 10 and developer tools. If you feel that we are missing any feature or functionality, my team would love to know at User Voice. And as always, we are keen to see what apps you are building for the Windows Store by tweeting @WindowsDev.

Source: Open Sourcing the Windows Bridge for iOS | Building Apps for Windows

See also: Windows Bridge for iOS: Let’s open this up - Windows 10 Forums