During the development of Windows 8, Microsoft called the new user interface the 'modern experience' to distinguish it from Windows 7's 'classic experience' [1, 2]. The term "modern" served as a placeholder to highlight the shift in design and functionality.
Microsoft developers abbreviated terms with the prefix "Mo," derived from "modern," which led to component code names such as "MoSh" for the modern shell, "MoSet" for Settings, and "MoPho" for the Photos app [1, 2]. As Raymond Chen explained, "Basically, they added ‘mo’ for ‘modern’ in front of everything, so the Metro shell became ‘MoSh’, the Settings application ‘MoSet’, and so on. And yes, the code name for the Photos application was exactly what it sounds like" [2].
Other early component names included "MoGo" for the Start menu, "MoBar" and "MoBody" for screen areas managing snapped and filled apps, and "MoCo" as the modern collection control, or ListView [1]. These codenames reflected the internal development focus on new user interface elements designed for touch and modern design paradigms.
Windows 8 was officially announced on June 1, 2011, marking the public introduction of these design changes 15 years before 2026 [1]. The development terminology highlighted Microsoft’s intent to pivot from the traditional Windows desktop toward a more touch-optimized experience.
The naming conventions and the "modern experience" branding provided a framework for implementing the new interface elements that defined Windows 8. Microsoft’s use of the "Mo" prefix extended systematically to key parts of the interface during development, underscoring the central role of this new user experience concept.
The June 2011 announcement remains a notable milestone that revealed Windows 8’s design direction to the wider public [1].