Develop hardware and low-level software that is compatible with Mac OS X and Apple hardware. Macintosh hardware implements standard busses such as ATA, PCI, USB, and FireWire that support high-performance peripherals and add-in cards. The I/O Kit, Apple's object-oriented environment for driver development, streamlines the development of device drivers and allows many devices to be controlled from applications without writing drivers at all. Additional kernel programming interfaces (KPIs) support development of nondriver kernel extensions (KEXTs).