At its Build 2014 conference on Wednesday, Microsoft announced universal Windows apps, which work across PCs, phones, tablets and even the Xbox One. In other words, the Windows runtime in Windows 8.1 Update 1 will be available to Windows Phone developers. This is a huge announcement for developers looking to build apps on Windows. David Treadwell, Microsoft CVP of Operating Sytems Group, talked about five areas the company focused on when trying to streamline the development process: User Interface, App Model, APIs, Tools, and Store. Treadwell explained that Microsoft understands developers want the bulk of the code to be the same regardless of which Windows platform they are targeting. At the same time, the company will be giving developers the option to make designs specific to each type of device.