Military & Aerospace Electronics has posted an overview of Real-Time Operating Systems (RTOS) favored by military designers. These are the operating systems being used in the latest military robotics systems such as UAVs, AUVs, UGCVs, and other robot acronyms. Along with the older RTOS systems such as LynxOS, QNX, VxWorks, the growing popularity of Linux and the inherently more secure nature of Open Source software is discussed.