The Facebook Windows 8 app was developed by using the XAML language
Even as the number of Windows 8 Modern apps in the Windows Store continues to grow, there appears to be a difference between what third party developers use in making those apps compared to Microsoft's own in-house creations.
ZDNet conducted a survey of the top 25 apps in the UK version of the Windows Store and found that 80 percent of them use the XAML language. That includes apps such as Facebook, Netflix, Google Search and more. Three of the top 25 apps use WinJS, including Microsoft's own Solitare Collection, along with Viber and Cut The Rope. One app on the list, Jetpack Joyride, was coded in C++. The survey was base on using a software tool created by the author of the article that scanned the apps to see which coding language was used.
By contrast, the vast majority of Microsoft's in-house Windows 8 apps use WinJS as its programming language, including nearly all of the Bing apps except for Bing Maps, which is coded in XAML. Microsoft's Camera and Reader app are also made by using XAML but others like Skype, the Windows Store itself and Xbox Live use WinJS.
Source: ZDNet | Image via Facebook