What is "dreamshell"

DreamShell is a Unix-like operating system, designed for the Sega Dreamcast video game console. It is based on KallistiOS libraries. Originally a command line interface with the ability to run third-party applications, later versions of DreamShell gained a GUI XML-module and support for applications written in the lua-scripts, with the ability to enhance their functionality by using functions of KLF-modules (analogous to DLL in Kallisti OS).