For many years, Microsoft (MSFT +3.06%) Windows was the overwhelmingly dominant platform, and software development was centered on the OS. Mobile devices have changed things: While Windows remains dominant on PCs, an enormous number of smart phones and tablets running Android and iOS have created far more options for developers.
Windows 8 and Windows Phone 8 were an attempt to bring developers back to Windows. A new kind of application, the "modern" or "metro" app, made it easier for developers to build applications for Windows. The same HTML and Javascript used for web apps could be used to build modern Windows apps, for example.
But it didn't really work that well. In Windows 8, modern apps are disconnected from the desktop, making them cumbersome to use on traditional PCs. They work better on tablets, but Windows tablets haven't exactly been selling like hotcakes. Windows Phone 8 suffered from not having a large enough install base for developers to take the platform seriously. While it has most of the major apps offered by other smart phone platforms, like Facebook and Pandora, there's still an enormous dearth of apps.
The one thing Microsoft needs to do in order to make Windows 10 a success is to get developers to treat the platform as a first-class citizen. The company is taking steps to make this happen, and the most promising development is the evolution of something that Microsoft first introduced in early 2014: universal apps.
Excel for Windows 10, running on a PC and a phone. Source: Microsoft.
Write once, run everywhere
Instead of developing a different version of an app for PCs, tablets, and phones, universal apps allow developers to create one app that can be run on any Windows 10 device. Some platform-specific code will be necessary, because the user interface on a phone will be different than on a PC; but the core logic of the app will be the same for each platform.
This idea of universal apps was first introduced by Microsoft in early 2014, and currently, developers can create universal apps that target both Windows 8.1 and Windows Phone 8. Windows 10 will expand on this idea, making the process easier and even allowing developers to target the Xbox One game console.
Windows 10 will bring a few key changes that should help developers and users see the value of universal apps. First, instead of having distinct app stores for different platforms, every Windows 10 device will have the same app store. Today, Windows 8 has a separate store from Windows Phone 8, meaning that users can't purchase an app once and use it on all of their devices. Windows 10 will fix this problem.
Second, the modern Windows apps from the store will run in a windowed environment on the Windows 10 desktop. There will be no disconnect between the old-style Windows applications and the modern ones like there was in Windows 8. This will eliminate the awkwardness of using modern Windows apps on the desktop.
Even the Xbox One will be able to run universal Windows 10 apps, creating the possibility that a game developer could target the PC, Windows Phone, and Xbox One without too much effort porting from one platform to another.
A huge install base
Windows Phone is in a difficult situation. Developers won't support it without a big install base, but it can't get a big install base unless developers support it in the first place. Windows 10 universal apps solve this problem by making the total install base of all Windows 10 devices the relevant figure. Even if the install base of Windows Phone is small, combined with Windows 10 PCs, tablets, and the Xbox One, the number of users capable of using a specific app explodes.
Microsoft giving away free Windows 10 upgrades to consumers currently running Windows 7 and Windows 8 should help rapidly grow the Windows 10 install base. Windows 7 still accounts for more than half of all Windows PCs in operation, and the free upgrade could lead to hundreds of millions of PCs being upgraded to Windows 10 within the first year.
Building a huge install base quickly is critical to getting developers on board. Windows 8 adoption was extremely slow, and Windows Phone 8 has a single-digit market share worldwide. If Microsoft can get hundreds of millions of devices on Windows 10 within the first year, it will be hard for developers to ignore the platform.
Universal apps are the key to the success of Windows 10, and Microsoft needs to make them seamless for both developers and users. The improvements made in Windows 10 so far seem to do just that, and the free Windows 10 upgrade should create a massive user base for developers. Windows 8 was an imperfect attempt at creating an operating system that could span all devices. Windows 10 is looking a lot better.
