The Zephyr® Project strives to deliver the best-in-class RTOS for connected resource-constrained devices, built to be secure and safe.

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  • Developed with security in mind
  • Includes CNA with PSIRT response team

Open Source

  • Available through the Apache 2.0 open source license
  • Free to use in commercial and non-commercial solutions

Product Ready

  • Long term support (LTS) with security updates
  • Auditable code base developed with a goal of safety certifications


  • Supports Bluetooth® Low Energy, Wi-Fi*, 802.15.4
  • Supports standards like 6LoWPAN, CoAP, IPv4, IPv6, Ethernet, USB, CAN and Thread

Complete flexibility & freedom of choice

  • Open source & neutral governance
  • Supports multiple hardware architectures
  • Small footprint: scales from small Cortex-M devices to multi-core 64-bit CPUs

Connect embedded devices securely to any cloud

  • Multiple protocol options including BLE mesh and Thread
  • Supporting industrial, automotive, smart city and smart home
  • Cloud agnostic – Connect with transport layer security to any cloud

Develop products with safety built in

  • Long-term support
  • In-depth security development lifecycle
  • Functional safety certification coming soon

350+ Boards Supported

Zephyr supports more than 350 boards. Search our list for the hardware used in your application. This diversity of supported boards gives developers and product manufacturers multiple options to solve their embedded RTOS challenges with Zephyr. If your board is not supported out of the box, adding support for a new board is simple.

Browse Supported Boards

As a founding member of the Zephyr Project, we are excited to support this latest release that brings new feature enablement and support to our expanding portfolio of i.MX RT crossover processors. The Zephyr 1.14 LTS release provides developers a well-tested, stable foundation for immediate project start and is based on a rich, open source microcontroller ecosystem that supports exciting new applications.

Maureen HelmNXP Microcontroller Software Architect and Zephyr Technical Steering Committee member

We are very excited to see that the Zephyr Project has gotten to the major milestone this LTS release is. Having the long term support option is something which is very often requested by our customers. This is especially the case for segments where development runs over longer times or for products with long lifecycles. Having the opportunity to introduce minor patches without rebasing the entire firmware framework is a major advantage for these users.

Paal KastnesTechnical Marketing Manager with Nordic Semiconductor

With the release of Zephyr 1.14 LTS, developers can focus on differentiation with the confidence that the software they are developing on always has the important fixes and latest security updates. Linaro is pleased to have helped drive the release which provides developers with a stable set of API for real world applications on constrained devices.

Kumar GalaLinaro IoT and Embedded Group (LITE) Technical Lead and Zephyr Project 1.14 LTS Release Manager

Platinum Members

Learn More About Membership

Zephyr project members help shape the direction of the project and provide guidance to help all members of the community get the most out of Zephyr.

Pull Requests Closed

Statistics last updated on October 17, 2021

December 2, 2021 in Blog, News, Top News

Why you should care about Zephyr RTOS

Written by Brendon Slade, Director MCU Ecosystem, NXP Semiconductors There are many reasons why developers should choose Zephyr RTOS. Beyond the features and security capabilities, there are some aspects, such…
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November 30, 2021 in Blog, News, Newsletter, Top News

The Zephyr Project Q4 Newsletter

Have you saved the date for the Zephyr Project Developer Summit? Did you know that the community moved all communications from Slack to Discord? Have you watched our newest videos…
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November 17, 2021 in Blog, News, Top News

Why IRNAS selected Nordic Semiconductor’s nRF Connect SDKs and Zephyr RTOS for RAM-1

IRNAS, the  institute for development of advanced applied systems, is the innovation lab for IoT devices, security services and other industrial solutions. Earlier this year, the company chose Nordic Semiconductor’s…
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November 11, 2021 in Blog, News, Top News

Zephyr OS LTS 2 Release Adds Full Platform Support for i.MX RT600 Crossover MCUs

Written by Brendon Slade, Director, MCU Ecosystem, NXP Semiconductors As a founding Platinum member of the Zephyr Project, NXP has been part of the fastest growing RTOS for years. We’re…
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