View the Zephyr Project code.

View the Zephyr Project Documentation Wiki.

How to Contribute

We are excited that you have decided to join us in contributing to the Zephyr Project!

Do also take the time to check our community guidelines and join in the conversations!

Learn more about our development model, development BKMs, coding conventions, etc.

Read the project documentation

Releases Overview

Updated versions of the Zephyr project are released approximately every three-months. Here are summaries for past releases.  See the Program Management wiki page for information about release planning and intermediate milestone dates.

Future Release Roadmap

Future release planning documentation is maintained in this live Zephyr Project GitHub roadmap.

While our expectations are for features to be completed in the release indicated, some features may be added to a release, moved to a different release, modified, or dropped altogether as further investigations and priorities are understood.

1.9 Release (September 2017)

  • Bluetooth 5.0 Support (all features except Advertising Extensions)
  • Bluetooth Qualification-ready BLE Controller
  • BLE Mesh
  • Lightweight Machine-to-machine (LwM2M) support
  • Pthreads-compatible API
  • BSD Sockets-compatible API
  • MMU/MPU (continued): Thread Isolation, Paging
  • Expand Device Tree support to more architectures
  • Revamp Testsuite, increase Coverage
  • Stack Sentinal support

1.8 Release (June 2017)

  • Tickless Kernel
  • BT 5.0 Features
  • Ecosystem: Tracing, debugging support through 3rd party tools
  • Improved Build and Debug
  • 3rd Party Compilers Support
  • Xtensa GCC support
  • Improved Build on Mac/Windows
  • MMU/MPU: Initial support (WIP)
  • Expand device support

1.7.1 Release (May 2017)

  • Updated TinyCrypt and mbedTLS
  • Bug fixes

1.7 Release (March 2017)

  • Unified Kernel continued
  • Direct Interrupt handling
  • CMSIS support
  • Native IP Stack
    • New Net and L2 APIs
    • Native protocols: MQTT, HTTP Library, CoAP (Zoap), NATS
  • Iotivity/OCF
  • Device Tree
  • Bootloader Support
  • Openocd support
  • RISC V Port
  • Xtensa Port


Zephyr project is provided as source code and build scripts for different target architectures and configurations, and not as a binary image. (See Supported Boards documentation for details.)  Updated versions of the Zephyr project are released approximately every three months. (See Release Overview for details.)

This downloads page is where you’ll find the latest tagged source code release along with its corresponding release notes found in the Zephyr Project GitHub repo.

All Zephyr project source code is maintained in a Git repository; you can either download source as a tar.gz file (see the bottom of the GitHub release notes pages listed below) or use Git.

The project’s technical documentation is also tagged to correspond with a specific release and can be found at