IncludeOS

IncludeOS is an open-source unikernel designed to run cloud services with a minimal footprint and no traditional general-purpose operating system. It focuses on packaging a single service into a self-contained image that combines the application code with a small, purpose-built kernel and runtime.

The core idea of IncludeOS is to compile an application's code together with a minimal operating environment into one bootable image. Developers write their service in C++ and link it with IncludeOS libraries. During the build, the application, kernel, drivers, and networking components are combined into a single executable image that can boot directly on supported virtualization platforms. This approach aims to reduce overhead, improve boot times, and limit the exposed attack surface by avoiding a full general-purpose OS.

Architecturally, IncludeOS provides a service-oriented runtime with a subset of standard libraries and a dedicated networking stack and device drivers tailored for cloud workloads. The result is a self-contained unikernel that runs without a separate host operating system, relying on the virtualization layer for hardware access, while exposing a clean API for networking, storage, and service management.

In deployment, IncludeOS targets cloud and virtualization environments and is commonly used for microservices and specialized network services. It emphasizes fast startup, predictable resource usage, and isolation between services. As a unikernel project, it sits among other research and production-oriented efforts aimed at reducing complexity and overhead in cloud deployments.

See also: unikernel, MirageOS, OSv, Rumprun.