Practical Internet of Things Security - Second Edition

Real-time operating systems

IoT devices often employ a Real-Time Operating System (RTOS) for process and memory management, as well as utility services supporting messaging and other communications. The selection of each RTOS is based on needed performance, security, and functional requirements of the product. There are many RTOS available, including those noted here:

TinyOS	Optimized for low-power embedded systems. A framework that incorporates components that support development of an application-specific operating system. Written in NesC, which supports event-driven concurrency. Refer to http://www.ann.ece.ufl.edu/courses/ee16935_10spr/papers/tinyos.pdf.
Contiki	Supports IP, UDP, TCP, and HTTP, as well as 6loWPAN and CoAP. ...