pretty BIOS GUI Interface - Unified Extensible Firmware Interface
The Unified Extensible Firmware Interface (UEFI) is a specification that defines a software interface between an operating system and platform firmware. UEFI is meant as a replacement for the BIOS firmware interface, present in all IBM PC-compatible personal computers. In practice, most UEFI images have legacy support for BIOS services. It can be used to allow remote diagnostics and repair of computers (and security exploits), even without another operating system. 
The original EFI (Extensible Firmware Interface) specification was developed by Intel. Some of its practices and data formats mirror ones from Windows. In 2005, UEFI deprecated EFI 1.10 (final release of EFI). The UEFI specification is managed by the Unified EFI Forum.