The Advanced Host Controller Interface (AHCI) specification describes the register-level interface for a host controller for Serial ATA. The specification includes a description of the hardware/software interface between system software and the host controller hardware. This specification is intended for hardware component designers, system builders and device driver (software) developers.
Implementation of the Advanced Host Controller Interface specification requires a license from Intel. Contributors of the Advanced Host Controller Interface specification for Serial ATA have signed the Advanced Host Controller Interface specification for Serial ATA - contributors agreement in order to be licensed to use and implement this specification. This contributors agreement provides Contributors with a reciprocal, royalty-free license to certain intellectual property rights from Intel and other Contributors for their products that are compliant with the licensed versions of the Advanced Host Controller Interface specification for Serial ATA.1