XMK – eXtreme Minimal Kernel

XMK – eXtreme Minimal Kernel – is a preemptive multitasking real-time operating system for embedded microcontrollers. What makes XMK different from other RTOSes is that XMK is designed to be small first, then scaled up to larger platforms. The BSD-licensed XMK is designed to be highly configurable and comes with a choice TCP/IP stacks: the tiny uIP stack or the more powerful but larger lwIP stack. XMK is available for a number of embedded platforms.