Microsoft to Developers: Project Reunion is the Best Path Forward

Microsoft has a dream, a dream that developers will build apps for all of its platforms with a single base of code. The company, for years, pitched the write once, run anywhere, idea to developers of Windows applications but the dream never materialized in a way that was widely adopted.

The most notable attempt at this is the company’s UWP platform that was charged with the task of creating a type of application that was safe, in the store, and available on all types of devices. But as the company’s mobile platform flatlined and the only ‘real’ Windows device that everyone is using today is a PC.

For the past couple of years, Microsoft has been slowly trying to modernize legacy apps with various “bridges” but the efforts have come up short. Further, the Microsoft Store was once a place only for UWP applications but that mandate has slowly fallen with some Win32 apps allowed in the store.

Which brings us to the announcements coming at Build 2020. The company is announcing project Reunion that as the name sounds, will bring Win32 and UWP applications much closer together.

So what does Reunion do? It continues the work the company has already started with the unification of UWP and Win32 APIs by making them decoupled from the OS, via tools like NuGet.  The result is a common platform for new apps and this should help with updating older apps, to new modern APIs, as well.

Microsoft is doing this so that there is a common platform for all apps as they are trying to remove the divide between UWP and Win32 apps. But what will these apps be called? Well, they certainly are not UWP apps and they aren’t quite Win32 either but there is no official name other than Windows apps. One thing is clear, if you are building a new app for Windows, going the “Reunion” route is going to be the best path forward, not UWP or Win32.

One of the unknowns right now is if these applications will be allowed into the store. While the company has opened up some of the previous restrictions, Reunion apps would be another step away from the initial vision of the app store.

One of the first components to support Project Reunion is WinUI 3 Preview 1. The new modern native UI framework for Windows means that developers can create a modern UI that scales and adapts across devices and it doesn’t matter if that’s for a new app or an existing one.

What Microsoft is promising with Reunion is that this will unify development for all 1 billion Windows 10 devices. Further, by decoupling the APIs from the OS, the company is making the promise that all version of Windows 10 will be able to run Reunion applications.

While the new Reunion functionality isn’t the first step Microsoft has taken to effectively bring UWP/Win32 together, it’s one of the first major public announcements that this is the direction the company is headed. The big question now is if developers will start using these new tools or sticking to the classic Win32 path is where everyone will stay for the long-haul.