The RIOT-OS is an open source IoT operating system designed to run on small low power devices. It provides the IoT stack and libraries to handle inputs/outputs, timers, sleep modes etc.
In one page of code it is possible to set up CoAP data and management resources and let the system manage the network etc like we do with big operating systems.
Emmanuel Baccelli, Cenk Gündogan, Oliver Hahm, Peter Kietzmann, Martine Lenders, Hauke Petersen, Kaspar Schleiser, Thomas C. Schmidt, Matthias Wählisch, RIOT: An Open Source Operating System for Low-End Embedded Devices in the IoT, IEEE Internet of Things Journal, Vol. 5, No. 6, pp. 4428-4440, December 2018.
Emmanuel Baccelli, Oliver Hahm, Mesut Günes, Matthias Wählisch, Thomas C. Schmidt, “RIOT OS: Towards an OS for the Internet of Things,” in Proceedings of the 32nd IEEE International Conference on Computer Communications (INFOCOM), Poster Session, April 2013.