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Zephyr is a small real-time operating system[3] for connected, resource-constrained and embedded devices (with an emphasis on microcontrollers) supporting multiple architectures and released under the Apache License 2.0. Beyond its kernel, Zephyr includes all the necessary components and libraries required to develop a full application such as device drivers, protocol stacks, filesystems and firmware update [4].

DeveloperLinux Foundation,
Wind River Systems
Written inC and assembly
OS familyReal-time operating systems
Working stateCurrent
Source modelOpen source
Initial release17 February 2016; 3 years ago (2016-02-17)[1]
Latest release1.14.0 LTS / 16 April 2019; 4 months ago (2019-04-16)[2]
Latest preview1.14.99 / 16 April 2019; 4 months ago (2019-04-16)
Marketing targetInternet of things
Available inEnglish
PlatformsARM (Cortex-M0, Cortex-M3, Cortex-M4, Cortex-M23, Cortex-M33, Cortex-R4, Cortex-R5), x86, x86-64, ARC, RISC-V, Nios II, Xtensa
Kernel typeMonolithic
LicenseApache 2.0
Preceded byWind River Rocket



In November 2015, it was originally developed as Rocket[5][6][7] kernel by Wind River Systems for Internet of things (IoT) devices.[8]

In February 2016, Zephyr became a project of the Linux Foundation.[9][1]

Since then, early members and supporters of Zephyr include Intel, NXP Semiconductors, Synopsys, Linaro[10], Texas Instruments, DeviceTone, Nordic Semiconductor, Oticon and Bose.[11]


Zephyr intends to provide all necessary components to develop resource-constrained and embedded or microcontroller-based applications. This includes but is not limited to[12]:

Configuration and build systemEdit

Zephyr uses Kconfig and Device tree as its configuration systems, inherited from the Linux kernel but implemented in Python for portability to non-Unix operating systems[13]. The RTOS build system is based on CMake, which allows Zephyr applications to be built on Linux, macOS and Microsoft Windows[14].


The kernel offers several features that distinguish it from other small OSes[15]:


A group is dedicated to maintaining and improving the security.[16] Also being owned and supported by a community means the eyes of the world's open source developers are vetting the code, which significantly increases Zephyr security.[9]

See alsoEdit


  1. ^ a b Zephyr Project: The Linux Foundation Announces Project to Build Real-Time Operating System for Internet of Things Devices, Linux Foundation, 17 February 2016
  2. ^ "Zephyr v1.14.0".
  3. ^ "Meet Linux's little brother: Zephyr, a tiny open-source IoT RTOS". 2016-02-17. Retrieved 2018-02-23.
  4. ^ ""Zephyr Project documentation: Introduction"".
  5. ^ "MCU Commercial Free RTOS for small embedded edge devices | Rocket". Retrieved 2018-02-23.
  6. ^ "Wind River Sets Rocket RTOS On Free Trajectory – EEJournal". Retrieved 2018-02-23.
  7. ^
  8. ^ Niheer Patel: Wind River Welcomes Linux Foundation’s Zephyr Project, Wind River Systems, 17 February 2016
  9. ^ a b Guerrini, Federico (2016-02-19). "The Internet of Things Goes Open Source with Linux Foundation's Zephyr Project". Forbes. Retrieved 2017-01-12.
  10. ^ Osborne, Charlie (2016-02-19). "The Linux Foundation's Zephyr Project: A custom operating system for IoT devices". ZDNet. CBS Interactive. Retrieved 2017-01-12.
  11. ^ ""Zephyr Project Members"".
  12. ^ ""Zephyr Project documentation: Introduction"".
  13. ^ ""scripts/ folder on GitHub"".
  14. ^ {{Cite web|url="Zephyr Project documentation: Application Development"
  15. ^ ""Zephyr Project documentation: Introduction"".
  16. ^ Wallen, Jack (2016-02-18). "Linux Foundation announces Zephyr Project, an open source IoT operating system - TechRepublic". TechRepublic. CBS Interactive. Retrieved 2017-01-12.

External linksEdit