There are a number of software operating systems available to run on connected devices to provide basic services to applications. While desktop and mobile computer operating systems are well known and stable, for example, Windows and Mac OSX, many operating systems used on connected devices are still under development with new projects appearing every few years.
Operating systems for connected devices used in the Internet of Things differ in interesting ways from desktop and mobile computers. One key problem to solve is balancing operating system complexity with all possible features a connected device might need.
For example, an operating system for a wall mounted thermostat might be much smaller and provide a small set of features instead of many capabilities needed by a desktop computer. An operating system also might be modular with a base operating system and modules to provide specific features. Developers mix the base operating system with only the modules they need to make the operating system as small and durable as possible.
Here are a few active operating systems used by connected devices if you want to explore features and how they work.
Brillo
This Google project takes the Android operating system used on phones and tablets and adapts it to work on connected devices. The primary benefit is familiarity: developers who create software applications for Android can more easily create software for small devices. It will use a protocol called Weave to make it easy for devices to connect to each other. The first versions of Brillo and Weave are expected to appear in late 2015 and early 2016.
Riot
Despite its name, Riot advertises itself as a friendly operating system for the Internet of Things. This is an open source project with the goal of providing a write once use anywhere operating system for connected devices. The project also emphasizes small code and memory footprints to make these devices faster and more durable.
Contiki
Contiki also is an open source project to create a modular, power efficient, and fast operating system for connected devices. The operating system is designed, for example, to work for long periods of time on devices powered by AA batteries, as well as manage power usage while waiting for messages to be relayed out and back to the connected device.
mbed
Created by ARM, a company that makes microprocessor chips used in connected devices, mbed is an operating system designed as a platform to provide a range of services to these devices. This project is interesting because the operating system is built to meet the needs of ARM customers who buy their chips.
Windows 10 IoT
Microsoft has an active program to adapt Windows 10 for Internet of Things devices, as well as Raspberry Pi and small micro-computers. It’s a strong effort and interesting to compare with efforts by Google and Apple.
In addition to these efforts, with the release of its Apple Watch, Apple also released HomeKit, a set of tools software developers can use to make devices smart through use of internet access. For software developers, coding for devices is similar to programming applications but they also must learn how to work with controller boards, computer chips, and other hardware.
Learn More
Project Brillo
https://developers.google.com/brillo/
http://www.anandtech.com/show/9294/google-announces-project-brillo-and-weave-for-iot
http://www.element14.com/community/groups/internet-of-things/blog/2015/07/23/brillo-and-weave-iot-operating-systems-and-android-m-is-google-is-taking-over-iot
Riot
Contiki
mbed
Operating Systems for the IoT: Goals, Challenges, and Solutions
An academic paper which describes the variety of problems operating systems for connected devices must solve.
http://www.researchgate.net/publication/236883971_Operating_Systems_for_the_IoT__Goals_Challenges_and_Solutions
Picking the right RTOS for your next-gen embedded IoT design
The title is a mouthful but the article describes how developers familiar with writing software for embedded devices think about adding the Internet of Things capabilities, what features are familiar or different.
http://www.embedded.com/electronics-blogs/cole-bin/4431815/Picking-the-right-RTOS-for-your-next-gen-embedded-IoT-design
Huawei LiteOS
A new operating system designed to work with the chips and other technology produced by this Chinese company.
http://eblog.huawei.com/all-you-need-to-know-about-liteos-and-smart-sensor-network
http://www.huawei.com/ilink/en/about-huawei/newsroom/press-release/HW_433506
Apple HomeKit
https://developer.apple.com/homekit/
http://www.businessinsider.com/apple-homekit-how-it-works-2015-9
Windows 10 IoT
https://dev.windows.com/en-US/iot
http://ms-iot.github.io/content/en-US/GetStarted.htm
https://www.youtube.com/channel/UCL7wy-iy_V76xxPnrIzGOZQ
http://blogs.windows.com/buildingapps/2015/04/29/microsoft-brings-windows-10-to-makers/
https://www.raspberrypi.org/blog/windows-10-for-iot/
http://blogs.windows.com/buildingapps/2015/09/24/whats-next-for-windows-10-iot-core/
http://www.adafruit.com/windows10iotpi2
