The ACPI Component Architecture (ACPICA) project provides an operating system (OS)-independent reference implementation of the Advanced Configuration and Power Interface Specification (ACPI). It can be easily adapted to execute under any host OS. The ACPICA code is meant to be directly integrated into the host OS as a kernel-resident subsystem. Hosting the ACPICA subsystem requires no changes to the core ACPICA code. Instead, a small OS-specific interface layer is written specifically for each host OS in order to interface the ACPICA code to the native OS services.