Award-winning technology backed by ground-breaking research
seL4 is both the world's most highly assured and the world's fastest operating system kernel. Its uniqueness lies in the formal mathematical proof that it behaves exactly as specified, enforcing strong security boundaries for applications running on top of it while maintaining the high performance that deployed systems need.
seL4 is grounded in research breakthroughs across multiple science disciplines. These breakthroughs have been recognised by international acclaimed awards, from the MIT Technology Review Award, to the ACM Hall of Fame Award, the ACM Software Systems Award, the DARPA Game changer award, and more.
Protecting critical systems around the globe
seL4 protects critical systems from software failures and cyber-attacks. It allows non-critical functionality to run securely alongside critical payloads by enforcing strong isolation and controlled communication.
seL4 is used in a wide range of critical sectors, from automotive, aerospace and IoT to data distribution, military and intelligence. It has been successfully retrofitted into complex critical systems and has demonstrably prevented cyber-attacks. Government organisations on several continents have funded further development of seL4 and its ecosystem.
Supported by commercial service providers
seL4 is the leading choice for building highly reliable software. Commercial support is available to help you build or migrate your product to run on seL4 and benefit from its unparalleled security.
A number of Trusted Service Providers have been endorsed by the seL4 Foundation for their expertise and experience in systems and/or formal verification at various levels: kernel, kernel platform ports, user-level Operating Systems components, and applications.
Backed by an Open Source Foundation
seL4 is open source, supported by the seL4 Foundation, an open, transparent and neutral organisation. The seL4 Foundation's goal is to ensure that seL4 continues to be the most highly-assured operating-system technology, readily deployable with a diverse and stable ecosystem of supporting services and products.
seL4 is free to use; its maintenance and development cost are funded by the seL4 Foundation memberships.
Contributions from a strong ecosystem
seL4 and its related technologies receive contributions from developers around the world.
The microkernel code itself evolves through a tightly controlled process, safeguarded by the Foundation's Technical bodies, to preserve its security, high assurance, and mathematical proofs.
Frameworks, tools and components that run on top of seL4 can use seL4's formally verified protection mechanisms and are therefore easier to assess for correctness. This means they can evolve more rapidly and accept community contributions at a higher pace, increasing the ease of adoption of seL4.
Annual gathering at the seL4 Summit
The seL4 Summit is the annual international conference on the seL4 microkernel and all seL4-related technology, tools, infrastructure, products, projects, and people.
It brings together the entire seL4 community to learn about the seL4 technology, its latest advances, uses, successes, challenges and plans. The event showcases exciting seL4 development, research, real world applications and experiences, offering an opportunity to connect with other seL4 developers, users, providers, customers, supporters, potential partners and enthusiasts.
Development Roadmap
With an active, public development roadmap, seL4 continues to solidify its position as the leading secure operating system and the industry standard for verified software. Evolution drives every level of the seL4 ecosystem:
seL4 itself is expanding its support for an increasing range of platforms, architectures, configurations and features.
The ecosystem is expanding with the development of frameworks, tools, components and language support to facilitate the production of seL4-based systems.
The formal proofs, which make seL4 unique, evolve alongside seL4. They are constantly maintained, improved, and kept in lock-step with the seL4 code.
Documentation and learning material
Eager to learn how to use and build on seL4 or its related frameworks and tools like Microkit, CAmkES, and Rust language support?
Explore the wide range of learning material for seL4, from hands-on tutorials and comprehensive documentation to research articles and university courses.
Latest News
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We are thrilled to announce our co-chairs, Lucy Fletcher and Robbie VanVossen, for the seL4 summit 2026, which will be held in Vancouver, late August - early September (dates TBC).
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Lucy Fletcher
Software Engineer, Apple
Lucy Fletcher is a software engineer at Apple based in Sydney, Australia, working on L4 microkernels and the surrounding ecosystems. Before joining Apple, she studied Computer Science at UNSW and worked with the Trustworthy Systems group, where she focused on the design and development of the seL4 device driver framework. Lucy is passionate about giving back to the seL4 community and supporting its continued growth. -
Robbie VanVossen
seL4 Technical Lead, DornerWorks
Robbie VanVossen is an employee of DornerWorks, has 12 years of experience in embedded hypervisors, and 10 years of experience with the seL4 microkernel. His work and leadership led to the development of aarch64 virtualization support across the seL4 ecosystem, both in the microkernel and the user-space libraries. He has also developed multiple projects using the Rust language, including embedded implementations of device drivers and applications. He has strong interests in embedded security, virtualization, seL4, and Rust.
We look forward to welcoming the community at the seL4 summit 2026!
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Videos of the seL4 Summit 2025 are now available on the seL4 YouTube channel! Links and slides can be found on the summit Program and Abstracts pages. Thanks to all the speakers for making the seL4 Summit 2025 a great success!
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The seL4 Foundation thanks Riverside Research for sponsoring the seL4 Summit 2025 reception.
Riverside Research recently acquired Cog Systems, a Founding Member of the seL4 Foundation.
Riverside Research is a national security nonprofit serving the DOD and Intelligence Community. Through the company's Open Innovation Center (OIC), it invests in multidisciplinary research and development and encourages collaboration. Riverside Research's areas of expertise include Object and Activity Detection; Accelerated AI/ML; Zero Trust; Open Architectures; Computational Electromagnetics; Plasma Physics; Precision Timing; Terahertz Imaging; Commercial Intelligence, Surveillance, and Reconnaissance (ISR); Collection Planning; and more. Learn more at www.riversideresearch.org.
See here if you are interested in sponsoring the seL4 Summit 2025.
