Microsoft has hit version 0.5 of Project Reunion, an initiative to provide developers with a unified set of APIs to cover both traditional Win32 desktop applications and the Universal Windows Platform (UWP) applications that run on Windows 10.
Project Reunion dispenses a unified set of APIs and tools designed to be used in a consistent way by any desktop app on a broad set of target Windows 10 OS versions. Version 0.5 is the first “production ready” release said Microsoft, and it plans to roll-out version 0.8 in the next few months and the official 1.0 release later in the year.
The problem that Project Reunion aims to address is that developers building Windows desktop apps have to choose between several app platforms and frameworks, and some features and APIs are only supported on specific frameworks. This is a legacy of the introduction of the UWP framework in Windows 10, which Microsoft intended to supersede the older Win32 APIs. Developers were reluctant to adopt a framework that meant applications would only run on Windows 10, however, and although older versions of Windows have now been retired, the issue persists.
Project Reunion tries get around this problem by providing a set of Windows APIs with implementations that are decoupled from the operating system itself. It delivers an extension for Visual Studio 2019 that includes project templates configured to use Project Reunion components in new developer projects.
These components include Windows UI Library (WinUI) 3, the next generation of the Windows user experience (UX) platform for Windows apps; MRT Core, a streamlined version of the modern Windows Resource Management System; and DWriteCore, which provides a device-independent layout system for text rendering.
More technologies will be added to Project Reunion this year, such as App Lifecycle for improved system performance and battery life; a modern Windowing system that combines Win32 windowing with the ease of UWP, notifications support for both local and push scenarios, and more.
Over time, Microsoft says it plans to make further investments in Project Reunion that will further remove distinctions between the different app models. Project Reunion will include both WinRT APIs and native C APIs, for example.