The Advanced Configuration and Power Interface (ACPI) specification is an open standard for unified operating system-centric device configuration and power management. ACPI, first released in December 1996, defines platform- independent interfaces for hardware discovery, configuration, power management and monitoring. The specification is central to Operating System-directed configuration and Power Management (OSPM); a term used to describe a system implementing ACPI, which therefore removes device management responsibilities from legacy firmware interfaces. The standard was originally developed by Intel, Microsoft, and Toshiba, and last published as "Revision 4.0", on June 16, 2009. Current developers also include HP and Phoenix.