Microsoft to devs: We want your iOS and Android apps

Earlier this week, Microsoft unveiled additional details for Universal Windows Platform Bridges, a set of technologies for converting existing Win32 apps, Android apps, iOS apps, and Web apps into Universal Windows Apps.

Universal Windows Apps — programs designed to run on Windows 10 across a gamut of devices — are a key part of Microsoft’s plan for latest revision of the OS. But legacy Windows apps may require more than the existing and offered toolkits to make the jump.

A four-lane bridge

Word of the toolkits came earlier this year at Build, where the four bridges were mentioned but not yet described in detail. Project Centennial wraps “classic” Windows apps (Win32, .Net) for Universal delivery; Project Islandwood allows iOS apps written in Objective-C to be ported to Windows by way of importing Xcode projects into Visual Studio.

Project Astoria converts Android apps by using “a Microsoft interoperability library to integrate Microsoft services into your app with very little effort.” And Project Westminster, explored in greater detail yesterday, allows Web apps — both online and off — to be encapsulated in a Universal Windows App.

The design of Astoria and Westminster both seem geared toward audiences that already have their own development stack of choice. In the blog post for Westminster, Microsoft describes how the programmer brings his own editor, repositories, and deployment service to the mix. Astoria, likewise, mentions in its blurbs that the programmer can use a “preferred IDE” to do the work.

Not all lanes open yet

By making it easy — or at least easier — to convert existing apps without having to rewrite them from scratch, Microsoft has two goals in mind. One is to make Windows 10 app development more open-ended by providing more roads into the ecosystem. The other is to do something about the Windows Store’s reputation for being a repository of underpowered, generally low-quality apps.

Porting existing iOS and Android apps is useful, although the novelty there is in how Microsoft, rather than a third-party app-development platform, is enabling the process. That said, the biggest payoffs and risks are in porting legacy Windows apps to the Store.

Some of those risks involve the way certain legacy Windows app behaviors don’t have counterparts in the Universal world. Brian Madden noted that with Project Centennial, apps that require privilege elevation — a UAC prompt — will not be permitted in the Windows Store. Because of that limitation, any applications that require their own kernel-level components or device drivers can’t be delivered through the Store.

Microsoft’s decisions to limit what Store apps can do may be less of a constraint for those writing apps from scratch. But until Windows apps with the full gamut of legacy capabilities can be delivered efficiently through the Store, Windows users — and admins — will continue to face disjointed app-installation and -admin experiences.