Microsoft has set an end-of-support date of April 7, 2027, for ASP.NET Core 2.3, the only supported version on .NET Framework, even though .NET Framework (and the original ASP.NET) will continue to be supported."After that date, Microsoft will no longer provide security patches, bug fixes, or technical support for ASP.NET Core 2.3," said principal product manager Daniel Roth. Users are advised to upgrade to modern ASP.NET on .NET 10.
The .NET Framework is the Windows-only version of .NET and is still maintained, though focused on stability rather than major new features. Version 4.8.1 is the latest release, which added native support for Arm64 as well as accessibility improvements for Windows Forms and WPF (Windows Presentation Foundation) applications. It is classified as a component of Windows and shares the Windows support lifecycle.ASP.NET Core was introduced at the same time as .NET Core, the current cross-platform variant of .NET, but the first version, released in 2016, could also run on the .NET Framework. That ability was dropped with the release of ASP.NET 3.0 in 2019. This is where the compatibility story gets confusing. The last version of ASP.NET Core to run on .NET Framework was 2.2, released at the end of 2018, but the last LTS (long-term support) release was 2.1, issued earlier in 2018. Developers with applications using features of 2.2 but running on .NET Framework were in a tough spot when it went out of support, the choice being to revert to 2.1 and fix compatibility issues, or upgrade to run on .NET Core.
