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.

1.6 Release (December 2016)

  • QMSI 1.3
  • Unified Kernel
    • New Kernel APIs with shims for old Kernel APIs
  • HW Crypt Offload
  • Native CoAP
  • Shell Improvements
  • USB Mass Storage
  • Power Management Enhancements for Quark SE
  • Nordic BLE Controller

1.5 Release (August 2016)

  • TCP Support
  • Integration of the Paho MQTT Library support with QoS
  • Flash Filesystem Support
  • Integration of the mbedTLS library for encryption
  • Improved BR/EDR support (for L2CAP, in particular).
  • Support for the Altera Nios II/f soft CPU architecture


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 and in the online release notes documentation.

Zephyr project source code is maintained in a Git repository.  For releases 1.14 and after, multiple repositories are used, so the preferred method for downloading source code is by using a Zephyr project tool called west.  While you can also download source as a tar.gz file or use Git commands (see the bottom of the GitHub release notes pages), this requires additional manual steps (see Using Zephyr without west documentation for details).

The project’s technical documentation is tagged to correspond with a specific release.  The latest documentation for the “master” branch under development can be found at Use the version selector to see the documentation for tagged versions.