In order to develop and test new hardware and low level drivers for that hardware, and a place to run diagnostics, “shells” are a critical necessity. In this paper the Unified Extensible Firmware Interface (UEFI) Shell 2.0, and shell applications which can be invoked by them, are described. In the UEFI Shell environment, applications are binary files that are loaded into memory, have their entry-point function called, and are then unloaded from memory.