Open Firmware
Open Firmware, standardized as IEEE 1275, is a system firmware that originated from Sun Microsystems' OpenBoot. It is implemented in the Forth programming language and utilizes (and originated) device trees for hardware description. Open Firmware is used in PowerPC-based Macintosh computers (excluding the initial Power Macintosh 6100 series), SPARC-based Sun Microsystems machines, and the x86-based OLPC project.