.NET 9 now available for RHEL and OpenShift

The .NET 9 release is now available, targeting Red Hat Enterprise Linux (RHEL) 8.10, RHEL 9.5, RHEL 10, and Red Hat OpenShift. Here's a quick overview of what developers need to know about this new major release.

New features in .NET 9

This release ships with the following features:

• The software development kit (SDK) supports using the latest C# (C# 13) and F# (F# 9) versions.
• The SDK now uses the new terminal logger by default which improves the usability of the .NET command-line interface.
• The base library, garbage collection (GC), and just-in-time (JIT) have seen many performance improvements. The GC now defaults to the dynamic adaption to application sizes (DATAS) mode which resizes the heap based on the active workload.
• .NET 9 comes with many API additions that improve performance, like overloads using the new C# 13 params Span, and allow C# 13 generic ref struct parameters to eliminate allocations. .NET 9 also includes many enhancements to its JSON support. For interoperability and efficient operations on AI data, .NET provides a new Tensor<T> type.
• ASP.NET Core 9 comes with built-in support for OpenAPI document generation. Additionally, the new MapStaticAssets middleware provides optimized support for delivering static assets.

How to install .NET 9

You can install .NET 9 on RHEL with the usual command:

# dnf install dotnet-sdk-9.0

The .NET 9 SDK and runtime container images are available from the Red Hat Container Registry. You can use the container images as standalone images and with OpenShift on all supported architectures:

$ podman run --rm registry.redhat.io/ubi8/dotnet-90 dotnet --version

9.0.100

Standard-term support for .NET 9

The .NET 9 release provides standard-term support for 18 months. Support will be available until May 2026.

Based on the .NET release schedule, the next version, .NET 10, will be a long-term support release. The release target date is November 2025, and it will provide three years of support.

The existing .NET 6 and .NET 8 releases provide support until November 12th, 2024 and November 10th 2026, respectively.

Additional support life cycle details are available on the .NET Life Cycle page.