Contiki system

Modules
	Argument buffer
	The argument buffer can be used when passing an argument from an exiting process to a process that has not been created yet.
	Clock library
	The clock library is the interface between Contiki and the platform specific clock functionality.
	Communication power accounting
	The compower module accumulates power consumption information and attributes it to communication activities.
	Callback timer
	The ctimer module provides a timer mechanism that calls a specified C function when a ctimer expires.
	Event timers
	Event timers provides a way to generate timed events.
	The Contiki program loader
	The Contiki program loader is an abstract interface for loading and starting programs.
	Multi-threading library
	The event driven Contiki kernel does not provide multi-threading by itself - instead, preemptive multi-threading is implemented as a library that optionally can be linked with applications.
	Contiki processes
	A process in Contiki consists of a single protothread.
	Real-time task scheduling
	The real-time module handles the scheduling and execution of real-time tasks (with predictable execution times).
	Seconds timer library
	The stimer library provides functions for setting, resetting and restarting timers, and for checking if a timer has expired.
	Contiki subprocesses
	A Contiki subprocess is a "process-in-a-process".
	Timer library
	The Contiki kernel does not provide support for timed events.
	The Contiki file system interface
	The Contiki file system interface (CFS) defines an abstract API for reading directories and for reading and writing files.
	Implicit network time synchronization
	This crude and simple network time synchronization module synchronizes clocks of all nodes in a network.
	Protothreads
	Protothreads are a type of lightweight stackless threads designed for severly memory constrained systems such as deeply embedded systems or sensor network nodes.