Our Company

Microkernel made in Germany

Kernkonzept GmbH is a midsize company providing secure and safe virtualization and operating-system technology. In addition to our microkernel-based L4Re Operating System Framework, we also offer comprehensive services around Linux and other open source operating systems. Our multinational team is based in Dresden, the capital of operating systems.

With unsurpassed knowledge and experience, our system engineers create solutions with real-time capabilities and virtualization support for complex software products.

We advise, guide and support our customers in safety-conscious industries like automotive or avionics as well as public institutions, providers of high-assurance and cloud security, server and embedded systems.

Our History

Where we started

First, some curious IT students built a microkernel that was different in every aspect. Out of the Fiasco microkernel we developed the L4Re Microkernel: lean, flexible, and with capability-based access control.

Around it, we created the L4Re Operating System, with the runtime environment (completing L4 with Re), native micro apps and userland services. Uniform APIs provide security by design.

With science-based standards, human values and a fierce love for the open-source framework L4Re, we grew into a renowned security software developing company. We are striving to give our best for your product, making the world better – as in safer and more secure.

Kernkonzept L4Re Consulting Support

Consulting and Support

We minimize your risks

We comprehensively advise you on all matters concerning hardware design, system architecture, system security, and operating systems – from Linux® to L4Re.

Our highly experienced operating system engineers create customized solutions for safety-critical applications. We guide you and your product through the certification and accreditation (Q&A) process, like ASIL or EAL4.

Kernkonzept L4Re Open-Source

Fast Start with L4Re

We are Open Source

We have deliberately decided to make and keep our L4Re Operating System Framework available under open source license (GPLv2).

Upon request, Kernkonzept can offer you dual licensing of your customized software, including commercial licenses.

Download L4Re and benefit immediately from instant availability!

Kernkonzept EU digital sovereignty

Public cyber security

We provide EU digital sovereignty

Secure connected devices and cloud security are vital for public cyber security.

Our L4Re OS Framework and Hypervisor is a solid base for German and EU digital sovereignty.

It is used in several NATO SECRET certified products and has been approved by BSI for processing information classified as German GEHEIM in 2024.

Designed from scratch

Tailor-made TCB

For your safe and secure applications we designed the L4Re Operating System Framework from scratch – being able to create a minimal trusted computing base (TCB), customized specifically for your product.

L4Re’s virtualization properties and the modular structure allow us to wrap every application of your computing system in safe compartments, giving protection through the strict temporal and local isolation.

In that way we design a system for you that meets highest security requirements. This works down to the smallest unit – the native L4Re MicroApps that allow to bring highly critical components into the system even without an operating system.

Our operating system uses multiple independent compartments to defend your architecture by effectively isolating each app and service to prevent an attack from spreading.

With our framework we can develop application specific L4Re Operating Systems and Hypervisors for any use-case – tailor-made uniquely for the demands of safety-critical applications in automotive, avionics, or security agencies.

Minimal, safe, secure

State-of-the-art L4Re microkernel

The founders of Kernkonzept designed the L4Re Operating System Framework to embody the Principle of Least Privilege. Our state-of-the-art, capability-based L4Re Microkernel and the whole framework range from user level to kernel level components, providing you with absolutely secure APIs – uniform across the whole system.

The small, lightweight code base of the L4Re Hypervisor can be formally verified to guarantee its protection.

We have been developing L4Re for decades, starting at TU Dresden, and are regularly joining research projects to evolve our system and explore new uses and features.


Minimal TCB for maximum security

The safety certification and security accreditation of a software’s source code is a complex process. It can use up far too much time and money, making the time to market for your product unpredictable.

More code lines mean a more complex certification process. This also significantly affects the fault tolerance of a product. On average there are up to 25 bugs for every 1.000 lines of code. That’s why we design our trusted computing base (TCB) as small and well-structured as possible. With around 30.000 lines our TCB is like mercury in relation to the sun – the big players’ source codes consisting of millions of lines.

Small but mighty: The L4Re minimal trusted computing base (TCB) delivers maximum safety, embedded security, and reliability. Obtaining certification and accreditation like Common Criteria/EAL4+, ISO 26262, or ISO 15408 is becoming much easier with our L4Re Operating System Framework.

Modular and lightweight

A framework for customized system solutions

Our modular L4Re Operating System Framework and Hypervisor can be used as a toolbox to design a minimal trusted computing base (TCB) made-to-measure for your needs.

The microkernel architecture provides small and well structured trusted components, allowing a full assessment of the security properties of the entire system.

Our operating system ensures the separation of applications while permitting flexible workloads and the reconfiguration of the system even during run time.

Minimize the number of certification cycles, costs and time to market for your safety-critical products and get unprecedented security.

Fully Customizable

Your own L4Re Operating System and Hypervisor

You produce safety and security applications for mission critical environments and connected devices – we make them safe to use without malfunctions and secure from attacks.

Our scalable, microkernel-based L4Re Operating System and hypervisor platform is the core of a certification-ready software system, providing you with a minimal attack surface, real-time capabilities, and virtualization support.

The L4Re Operating System Framework and Hypervisor protect your critical applications, mission critical environments and connected devices.