In a mere 380 bytes, Itsy implements an operating system kernel with memory management and pre-emptive task switching. From the website:
Itsy-OS v0.1 is a small 8086 operating system kernel providing two basic services: a simple preemptive task switcher and memory management. If necessary, simple IPC and task management can be added to provide the features of a traditional microkernel.
(Source: retroprogramming.com)
