10 Essential Things to Know About .NET on Ubuntu 26.04 Resolute Raccoon

By ● min read

<p>Ubuntu 26.04 LTS (Resolute Raccoon) has officially launched, bringing the latest .NET 10 LTS as a first-class citizen. Whether you're a seasoned .NET developer or just exploring cross-platform development, this release tightens the integration between Microsoft's runtime and Canonical's operating system. Below are ten key facts every developer should know about .NET on Ubuntu 26.04—from installation to container strategies and under-the-hood changes.</p> <h2 id="item1">1. .NET 10 LTS Comes Pre-Integrated in Ubuntu 26.04</h2> <p>The headline feature for .NET enthusiasts is that Ubuntu 26.04 ships with .NET 10 as its default LTS version. This means you can start building and running .NET applications immediately after a fresh install. Canonical and Microsoft have collaborated to ensure that the runtime and SDK are fully optimized for the new kernel and libraries, offering a seamless experience for both development and production workloads.</p><figure style="margin:20px 0"><img src="https://devblogs.microsoft.com/dotnet/wp-content/uploads/sites/10/2026/04/whats-new-for-dotnet-in-ubuntu-2604.webp" alt="10 Essential Things to Know About .NET on Ubuntu 26.04 Resolute Raccoon" style="width:100%;height:auto;border-radius:8px" loading="lazy"><figcaption style="font-size:12px;color:#666;margin-top:5px">Source: devblogs.microsoft.com</figcaption></figure> <h2 id="item2">2. Installation via APT is One Command Away</h2> <p>To install the .NET 10 SDK, simply run <code>sudo apt update && sudo apt install dotnet-sdk-10.0</code>. The package is hosted in Ubuntu's official repositories, so no extra PPAs are required. This command pulls in all necessary dependencies, including the runtime, ASP.NET Core, and SDK tools. For headless environments or runtime-only scenarios, you can alternatively install <code>dotnet-runtime-10.0</code>.</p> <h2 id="item3">3. .NET 8 and 9 Are Available via Separate Feeds</h2> <p>If your application targets .NET 8 or 9, you can still use them on Ubuntu 26.04. Canonical provides a dedicated Personal Package Archive (PPA) for older .NET versions. Add the feed with <code>sudo add-apt-repository ppa:dotnet/backports</code>, then install the specific SDK or runtime packages. This ensures compatibility with legacy projects while still benefiting from the new OS.</p> <h2 id="item4">4. Container Images Are Tagged for Quick Upgrades</h2> <p>For containerized workloads, .NET 10+ images now use the <strong>resolute</strong> tag. If you were previously using the <code>noble</code> tag (for Ubuntu 24.04), simply update your Dockerfile to reference <code>mcr.microsoft.com/dotnet/sdk:10.0-resolute</code> or <code>mcr.microsoft.com/dotnet/aspnet:10.0-resolute</code>. This change aligns with Ubuntu's LTS naming and makes it easier to track OS updates.</p> <h2 id="item5">5. Kernel Bump to Linux 7.0 Brings Performance Gains</h2> <p>Ubuntu 26.04 ships with Linux kernel 7.0, which introduces improvements in scheduling, memory management, and I/O. Microsoft has already started testing .NET against kernel 7.0 in their CI pipelines. While early results show no regressions, developers can expect better throughput for high-load applications. Note that older .NET versions (8 and 9) remain fully compatible with the new kernel.</p> <h2 id="item6">6. Post-Quantum Cryptography Support Arrives</h2> <p>In .NET 10, Microsoft added support for post-quantum cryptographic algorithms, and Ubuntu 26.04 leverages this via the updated OpenSSL libraries. This means that applications using System.Security.Cryptography can now negotiate quantum-resistant key exchanges—a critical feature for future-proofing secure communications. Developers should review their TLS configuration to enable these algorithms.</p><figure style="margin:20px 0"><img src="https://uhf.microsoft.com/images/microsoft/RE1Mu3b.png" alt="10 Essential Things to Know About .NET on Ubuntu 26.04 Resolute Raccoon" style="width:100%;height:auto;border-radius:8px" loading="lazy"><figcaption style="font-size:12px;color:#666;margin-top:5px">Source: devblogs.microsoft.com</figcaption></figure> <h2 id="item7">7. Cgroup v1 Removal Simplifies Container Management</h2> <p>Ubuntu 26.04 drops support for cgroup v1, fully adopting cgroup v2. .NET has supported cgroup v2 for years, so existing containerized apps should work without changes. However, if you rely on custom cgroup v1 setups, you'll need to migrate to the v2 API. The switch reduces kernel complexity and improves resource accounting for container orchestration tools like Kubernetes.</p> <h2 id="item8">8. Microsoft's CI Validates .NET on Ubuntu 26.04 at Scale</h2> <p>Every pull request in the dotnet/runtime repository runs validation on Ubuntu 26.04 container images. In fact, Microsoft might be one of the largest consumers of these pre-release images. This continuous testing ensures that .NET works flawlessly on the new OS from day one. Developers can trust that the runtime has been battle-tested against the exact packages shipped in Resolute Raccoon.</p> <h2 id="item9">9. Run C# Directly in a Container with Heredocs</h2> <p>One of the slickest demos is running C# code without creating a project file. Inside an Ubuntu 26.04 container, you can use a heredoc to pipe code into <code>dotnet run</code>. For example: <code>dotnet run - &lt;&lt; 'EOF'</code> followed by your C# source. This pattern is especially useful for AI agents and scripting—showing that C# has the same ergonomics as Python for quick experiments.</p> <h2 id="item10">10. Container Flavors Remain Unchanged—Chiseled Images Included</h2> <p>The new resolute images maintain the same distribution flavors as noble, including Chiseled Ubuntu images. Chiseled images offer minimized attack surfaces by removing unnecessary packages. They work with the host kernel (e.g., a 26.04 container on a 24.04 host uses Linux 6.x kernel). No changes to your Dockerfile are needed beyond updating the base image tag.</p> <p>Ubuntu 26.04 Resolute Raccoon solidifies .NET as a premier development platform on Linux. With integrated .NET 10, enhanced cryptography, and streamlined containers, the partnership between Microsoft and Canonical continues to mature. Whether you're migrating existing apps or starting new projects, this LTS release offers a stable, high-performance foundation for years to come.</p>