MultiBoot USB
This is a collection of GRUB scripts that allows to create a bootable pendrive (USB dongle, flash stick) supporting a number of different OS images. Simply copy ISO files under `/iso-imgs`. Both UEFI and Legacy BIOS boot modes can be enabled simultaneously.
KolibriOS is a tiny open-source operating system with a monolithic preemptive kernel and video drivers for 32-bit x86 architecture computers. KolibriOS is a fork of MenuetOS, written entirely in FASM (assembly language). However, C, C++, Free Pascal, Forth, among other high-level languages and compilers, can also be used in application development. KolibriOS features a rich set of applications that include a word processor, image viewer, graphical editor, web browser, and over 30 games.