If you’re here, you likely already know about preemption, determinism, and real-time capable operating systems. If that’s the case, and you want to learn how to get up and running with Real-time Ubuntu, skip ahead now to find out how to enable the kernel on your workstation.If you’d like a short refresher, we have a three-part blog series on real-time Linux for beginners. On the other hand, if you’re more interested in the business impact a real-time OS can have across industries, this whitepaper explains the benefits of real-time compute for enterprises, explores industry use-cases, and will show you how to unlock the potential of real-time compute in your business. And, finally, if you’re more technically savvy, this CTO’s guide to real-time Linux is probably what you’re looking for.Real-time Ubuntu is Ubuntu with a real-time kernel, which includes the PREEMPT_RT patchset. It changes Linux’s default scheduler to a priority-based one, increasing predictability by modifying the existing kernel code. As a consequence, Real-time Ubuntu is more pre-emptive than mainline, delivering determinism and lower latency.Available Versions and Long-Term SupportReal-time Ubuntu is available across both LTS and interim Ubuntu releases, offering flexibility to individual developers and enterprises alike to experiment with the latest software and features, while having the peace of mind of support. Open access to Real-time UbuntuThe deb packages of various Real-time Ubuntu releases, from 22.04 LTS to the interim 25.04, have been openly released and are now available for free for anyone to access. Anyone can install them via the Ubuntu Universe repository, an archive which makes it easy to install new software tested and built specifically for each version of Ubuntu. VersionCode nameReal-time Kernel VersionAccessUbuntu 25.04Plucky Puffin6.14Source packageUbuntu 24.10Oracular Oriole6.11Source packageUbuntu 24.04 LTSNoble Numbat6.8Source packageUbuntu 22.04 LTSJammy Jellyfish5.15Source packageTable 1: Releases of Real-time Ubuntu available in the Universe repository For open access to the real-time kernels above available in Universe: sudo add-apt-repository universe sudo apt update sudo apt install ubuntu-realtimeNote that the Universe repository contains community-maintained free and open-source software, and only a teaser of the real-time kernel is available in Universe for LTS releases. To receive updates for the LTS samples, an Ubuntu Pro subscription is necessary.While the real-time kernel packages are openly available and provide a great way to test real-time capabilities ahead of the next LTS, developers and enterprises deploying to production can receive security patching for all the software in the repository for 10+ years with Ubuntu Pro. Ubuntu Pro is a subscription for open-source software security by Canonical, providing security and compliance on top of Ubuntu LTS, with 10+ years of coverage for over 25,000 packages.Ubuntu Pro is always free for personal use, and anyone can use it for free on up to 5 machines, or 50 if you are an official Ubuntu Community member. Furthermore, enterprises receive a 30-day trial.LTS Releases of Real-time Ubuntu Server with Ubuntu ProCanonical provides up to 12 years of security maintenance and a continuous stream of critical updates to the real-time kernel variants for Ubuntu LTS versions under the Ubuntu Pro subscription. The generic release of Real-time Ubuntu is available on AMD64 and ARM64, whereas silicon-optimised variants are available on Intel hardware (22.04 LTS with support for Intel Time Coordinated Computing and IEEE 802.1 Time Sensitive Networking ), and Raspberry Pi.VersionCode nameReal-time Kernel VersionVariantsUbuntu 22.04 LTSJammy Jellyfish5.15generic, Intel-optimisedUbuntu 24.04 LTSNoble Numbat6.8generic, Raspberry-Pi optimisedTable 2: LTS Releases of Real-time Ubuntu Server If you’re using an LTS release of Ubuntu and have Ubuntu Pro enabled, enabling the real-time kernel is straightforward. First, if you have not yet attached your machine to an Ubuntu Pro subscription, you will need to do so in order to enable Real-time Ubuntu. You can do so by running the following command:sudo pro attachOtherwise, select the correct version for your OS and processor, and use the corresponding commands below to enable the appropriate kernel variant:Generic on Ubuntu 22.04 LTS or Ubuntu 24.04 LTS:sudo pro enable realtime-kernelRaspberry Pi 4 or 5 on Ubuntu 24.04 LTS:sudo pro enable realtime-kernel --variant=raspiOptimized Real-time Ubuntu is production-ready on Intel Atom® X6000E Series Processors, as well as 11th, 12th and 13th Gen Intel® Core™ processors: Intel Atom and Intel Core processors on Ubuntu 22.04 LTS:sudo pro enable realtime-kernel --variant=intel-iotgReboot your system, and you’re ready to run Real-time Ubuntu.LTS Releases of Real-time Ubuntu Core The real-time kernel is also available for Ubuntu Core, Canonical’s embedded version of the Ubuntu OS. Ubuntu Core is Ubuntu for IoT and embedded devices, with a strong focus on robust security, a streamlined update mechanism, and a simplified developer experience. While Ubuntu Core is similar to standard Ubuntu – open source, binary-compatible and backed by a strong developer community – it is specifically designed for the world of embedded and cybersecurity compliance. Ubuntu Core VersionReal-time kernel versionCore 225.15Core 246.8In order to run Ubuntu Core with the real-time kernel, we first need to create and build a Real-time Ubuntu Core image.Let’s get you to productionCanonical delivers Real-time Ubuntu with the same commitment to security, stability, and open-source leadership as the rest of the Ubuntu ecosystem. With deterministic performance, long-term support, and easy access across edge and cloud environments, Real-time Ubuntu enables enterprises to focus on their value proposition.We partner with silicon vendors, board manufacturers and ODMs to shorten enterprises’ time-to-market. Reach out to our team for custom board enablement, commercial distribution, long-term support or security maintenance.https://ubuntu.com/kernel/real-time/contact-usFurther Readinghttps://ubuntu.com/engage/cto-guide-real-time-kernelhttps://ubuntu.com/engage/real-time-os-whitepaperhttps://ubuntu.com/engage/cra-yocto-core