Stabilnemu

Stabilnemu is an open-source project that provides a deterministic runtime environment designed to stabilize software behavior across different hardware and host configurations. By intercepting and controlling timing, I/O, and resource scheduling, Stabilnemu reduces non-determinism that commonly affects debugging, testing, and reproducibility. The project targets developers, testers, and researchers who require repeatable results in complex software stacks.

Stabilnemu originated as a community effort to address flaky tests and intermittent bugs caused by hardware differences and system timers. It is maintained in a public repository with contributions from individuals and organizations. The project is cross-platform and aims to support common host environments, with ongoing work to broaden compatibility and improve performance.

The core architecture comprises a lightweight orchestrator, an emulation layer, and a plugin system. The orchestrator manages lifecycle and configuration; the emulation layer intercepts system calls, timers, and peripheral access, providing deterministic alternatives or stubs. Plugins add support for hardware peripherals, networking, and file systems, enabling representative environments without full hardware virtualization. Stabilnemu integrates with existing hypervisors and container runtimes, offering sandboxed execution and trace collection.

Usage scenarios include debugging nondeterministic bugs, validating CI pipelines, teaching and research, and prototyping hardware interactions in software without dedicated hardware. Licensing is open-source, with governance focused on code quality and security.

See also deterministic debugging, virtualization, emulation, and reproducible builds.