Staemu

Staemu is an open-source software library that provides a framework for state management and timing in emulation and simulation projects. It aims to simplify saving, loading, and synchronizing the state of an emulated system, and supports features such as frame stepping, pausing, and rewinding.

Key features include a serialization API for device and memory state, deterministic timekeeping, and an event-driven execution model. The library is designed to integrate with CPU cores, memory subsystems, graphics and audio pipelines, input devices, and peripheral emulation. It offers cross-platform bindings and a modular plugin architecture to allow projects to implement or replace components.

Design and architecture emphasize small, well-defined interfaces, version-stable state formats, and careful separation between core timing and device emulation. It supports incremental or differential save states, and aims to minimize performance overhead while preserving determinism where required by the emulator’s design.

Usage and impact: Staemu is used by hobbyist and academic emulation projects to implement features such as save states, slow-motion, and deterministic playback. It provides a common foundation that reduces duplication across projects and facilitates learning and experimentation with emulation architectures.

History and licensing: Staemu originated in community-driven development for emulation tools and is maintained on public repositories with contribution guidelines. It is released under an open-source license, inviting developers to contribute, report issues, and participate in governance and documentation efforts.