MenuetOS is a compact and lightweight operating system designed for 32-bit x86 compatible computers. It is written entirely in the assembly language, making it one of the smallest operating systems in the world. MenuetOS is a real-time, modular, and preemptive multitasking operating system with a graphical user interface and many features. It includes a kernel, a text editor, a graphics editor, a web server, and a TCP/IP stack. It has a graphical boot menu, and users can select the operating system to be loaded. It also supports USB and network booting. MenuetOS is suitable for use in embedded systems, as it can be easily configured to perform specific tasks. It is open source and is available as a free download.
Discontinued It seems that the project is no longer updated (no release candidate since 2012, no stable release since 2008), but still fully functional.