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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The seL4 Foundation, launched in 2020 as a project under the Linux Foundation, has benefited from early support in governance, trademarks, and operations. As the community has grown, the seL4 Board has determined that greater independence will better serve its members and long-term goals.
To support broader outreach and stronger community engagement, the seL4 Foundation has transitioned to a new, independent legal entity, established as a Swiss-registered non-profit association (Verein). The purpose, principles and internal structure remain unchanged. Switzerland was chosen for its neutrality and its well-established framework for international non-profits, a model also used by organizations such as RISC-V International.
This strategic move is set to position the seL4 Foundation for continued growth and improved accessibility for its global community.
If you are not already a member, join now to shape the future of the seL4 ecosystem!
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We are pleased to announce that the seL4 Summit 2026 will be held in Vancouver, Canada, 1 - 3 September (informal social activities on 31 August).
Meet the Program Committee
Our team comes from various parts of the seL4 ecosystem: users, contributors, committers, experts, advocates, researchers, and engineers.
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Robbie VanVossen
(co-chair)DornerWorks
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Lucy Fletcher
(co-chair)Apple
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Adam
NCSC
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Corey Lewis
Proofcraft
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David Cock
Neutrality
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David Hardin
Collins
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Gernot Heiser
UNSW Sydney
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Juliana Furgala
MIT Lincoln Laboratory
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Leigha VanderKlok
DornerWorks
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Lesley Rossouw
UNSW Sydney
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Martin Dehnel-Wild
Kry10
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Nick Spinale
Colias Group
We will announce a Call for Presentations early in 2026. Stay tuned!
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26 Nov 2025
We’re pleased to announce the release of
- seL4 14.0.0: The seL4 microkernel
- Microkit 2.1.0: The seL4 Microkit for building static-architecture systems
- CAmkES 3.11.1: Component Architecture for microkernel-based Embedded Systems
- capDL 0.4.0: Tools for generating, parsing and loading capability distribution specifications
- rust-sel4 3.0.0: Rust support for seL4 userspace. See the Rust section on the seL4 docsite for more information.
seL4 14.0.0 and the corresponding Rust support come with new features and will require updates if you are using the seL4 API directly. Microkit and CAmkES abstract those and should not require any update of user code compared to Microkit 2.0.1 and CAmkES 3.11.1.
Enjoy!
