Microsoft’s .NET strategy may have been a little unclear recently, with two distinct strands of development in the familiar .NET Framework and the new, open-source .NET Core. A common set of .NET Standard libraries aimed to bring the two together, giving developers a single way to work with any of the different .NET versions on all their target platforms, from Windows to mobile to the web. But that still meant having to think about which .NET runtime to use: Core, Xamarin, Mono, or Framework?
Introducing .NET 5, the future of .NET
At Build 2019 Microsoft unveiled its plans for the future of .NET, announcing that the next major release after .NET Core 3 would be a single version of .NET called .NET 5. Building on the rapid growth in the refactored and reinvigorated .NET Core, Microsoft aims to have many existing .NET Framework 4.8 APIs and features run on .NET 5, along with new APIs and services. It’s not only the base class libraries that are converging; Microsoft is taking the opportunity to bring its different .NET compilers together, evolving both .NET Core’s JIT (just-in-time) and Mono’s ahead-of-time compilation models.
It’s not a surprising decision. The .NET Framework wasn’t advancing as quickly as .NET Core, weighed down by legacy code. That, combined with Microsoft’s growing focus on cross-platform development, ensured that a decisive move from the nearly twenty-year-old Framework to the newer Core was inevitable. Dropping Core from the name is logical, too. With the APIs added since launch and support for the .NET Standard libraries, .NET Core really isn’t a cut-down core refactoring any more. With .NET 5 signaling the end of development for the .NET Framework, it’s clearly time for a new name.
Even so, it’s not going to be an overnight change. .NET Core 3 is still to ship, and we won’t see .NET 5 until the fall of 2020. A planned ship date of November 2020 gives us nearly 18 months to get our code ready, with preview versions available some time in the first half of 2020.