Microsoft’s Windows API unification project moves forward

Microsoft’s Windows API unification project moves forward

Project Reunion 0.5 Preview provides unified set of APIs and tools for building desktop apps that target a broad set of Windows 10 OS versions

Credit: Dreamstime

Microsoft has launched a developer preview of Project Reunion, the vendor's attempt to smooth out inconsistencies that have emerged in developing Windows applications.

Project Reunion 0.5 Preview, introduced on March 9, is not supported for building apps to be used in production environments. But developers are encouraged to try it with the knowledge that the project will change in many ways between now the version 1.0 release. Instructions for getting started with Project Reunion can be found at

Unveiled in May 2020, Project Reunion aims to reunite aspects of Windows development, including desktop APIs, Win32 APIs, and Universal Windows Platform APIs, and provide APIs and tools to be used in a consistent way by any desktop app on a broad set of Windows 10 OS versions.

The project is an attempt to eliminate the need for developers to use different versions of APIs for different Windows versions and the difficulties developers have in rolling out new features when they are unsure of which Windows versions to target.

Project Reunion does not replace existing desktop Windows platforms, frameworks, and APIs such as .NET, Windows Forms, Windows Presentation Foundation, and C++/Win32.

The project instead complements existing platforms with a common set of APIs and tools that will work across all these platforms. Project Reunion’s Windows APIs are decoupled from the OS and released via NuGet packages.

Project Reunion .05 Preview contains Windows UI Library 3, the next generation of the Windows user experience for desktop and UWP apps. This is in addition to MRT Core, a streamlined version of the modern Windows Resource Management system and DWrite Core, an implementation of the DirectWrite API that provides access to DirectWrite features for text rendering including a device-independent text layout system, hardware-accelerated text, multi-format text, and wide language support.

Follow Us

Join the newsletter!


Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags MicrosoftWindows



Join key decision-makers within Environmental, Social, and Governance (ESG) that have the power to affect real change and drive sustainable practices. SustainTech will bridge the gap between ambition and tangible action, promoting strategies that attendees can use in their day-to-day operations within their business.

EDGE 2023

EDGE is the leading technology conference for business leaders in Australia and New Zealand, built on the foundations of collaboration, education and advancement.


ARN has celebrated gender diversity and recognised female excellence across the Australian tech channel since first launching WIICTA in 2012, acknowledging the achievements of a talented group of female front runners who have become influential figures across the local industry.

ARN Innovation Awards 2023

Innovation Awards is the market-leading awards program for celebrating ecosystem innovation and excellence across the technology sector in Australia.

Show Comments