Developers of certified, safety-critical avionics software face many challenges. A key challenge arises when software developed for one system is reused in another system. Given the features and capabilities of most Commercial-Off-The-Shelf (COTS) safety-critical Real-Time Operating Systems (RTOSs), reusing software in a different target environment means modifying that software and re-incurring costly certification activities (e.g., DO-178B ). This paper discusses some of the unique features of DDC-I's Deos: a time and space partitioned, safety-critical RTOS. Using these features, safety-critical software developers can reconfigure and adapt their software for reuse in new systems without the need to modify that software and incur costly re-certification activities.